# Shared Flashcard Set

2R051 CDC Vol 3
FOUO
199
Archaeology
Professional
06/29/2010

## Cards Return to Set Details

Term
 What are natural numbers?
Definition
 Any whole number from 0 to infinity
Term
 What is the general rule of operations when working with a grouping of numbers with no symbols?
Definition
 PEMDAS- Multivide divide left to right then add or subtract
Term
 What are signed numbers
Definition
 values (pos+) or neg(-) the + or - being the signs.
Term
 How do you add two numbers with different signs?
Definition
 Subtract the smaller from the larger
Term
 What is the result when one negative number is divided by another negative?
Definition
 Politive
Term
 What is a good rounding rule?
Definition
 round only the final answer
Term
 How is the rate determined?
Definition
 R=P/B
Term
 How is portion determined?
Definition
 P=R/B
Term
 How is base determined
Definition
 B=P/R
Term
 What statistical method is considered objective, subjective?
Definition
 Descriptive and Inferential
Term
 In the function M=F(N) which is independant? Dependant?
Definition
 M-dependant N-indpendant
Term
 What are subscripts for?
Definition
 to differentiate variables in a series
Term
 What is the meaning of the symbol Sigma? (backwards E-ish)
Definition
 sum of all aforementioned figures
Term
 What is the value of 2 to the 5th power equal? Which is base? Exponet?
Definition
 2 base 5 exponet, 62
Term
 What is the range of the values of N in this expression? 5 less than or equal to N which is less than or equal to 15
Definition
 5-14
Term
 What is the value of 5/2*6?a. 0.3b. 8.4c. 15d. 30
Definition
 C. 15
Term
 Compute the difference of the signed numbers: -17-(-10)a. 3b. -3c. -7d. -27
Definition
 C.
Term
 Eighty is 40% of what numberA. 200b. 820c 400d 500
Definition
 a
Term
 what statistical method uses only a sample of data?a inferentialb descriptivec data surveyd randomization
Definition
 A
Term
 Which action would require the use of the descriptive statistics methoda. draw a conclusion about datab. chose a random sample of datac. summarize a large amount of datad. generalize from the results of small samples
Definition
 c.
Term
 In the equation Y=X+2 what does Y represent?a. exponetb. inequalityc. subscriptd. variable
Definition
 d
Term
 What is the value of 4 to the 3rd power
Definition
 B
Term
 What do you call data that can be expressed only in whole number units?
Definition
 Discrete
Term
 What is the meaning of "population" as used in statistical language
Definition
 the body from which the population was drawn
Term
 Define parameters
Definition
 limits or barriers of a population
Term
 What is a sample?
Definition
 Splinter of the whole, chosen to represent a population
Term
 What is a random sample?
Definition
 Where ever unit has the equal chance of being drawn
Term
 Define stratified sampling
Definition
 Homogenity in groups, heterogenity out of groups
Term
 Explain the difference between intentional and unintentional bias
Definition
 Intentional- purposeful selection, going somewhere with it. Unintentional- dumb. Not following 6Ps
Term
 Name two measurements that are truly quantitive
Definition
 Nominal, Interval
Term
 Name two measurement scales that are non quantitative
Definition
 Rational, Ordinal
Term
 What is the function of a frequency distrobution?
Definition
 Organize data logically
Term
 What is the first step in making a frequency distribution?
Definition
 Correlate data
Term
 What is the reccomended number of classes in a frequency distribution?
Definition
 12-20
Term
 What happens to a frequency distribution if the class interval is too small?
Definition
 Skewed
Term
 Explain cumulative frequency distibution
Definition
 Figures outside boundaries
Term
 How are percentage frequencies determined?
Definition
 Class frequency/all frequency
Term
 What are histograms based on
Definition
 The fact that values fall evenly, inside limits
Term
 Where are the frequencies of the class intervals plotted when constructing a frequency polygon?
Definition
 Corresponding midpoints
Term
 Which graphic representation gives a better idea of the general shape of a distribution?
Definition
 Frequency polygon
Term
 Define the mode
Definition
 The most frequently occuring value
Term
 List the five characteristics of the mode
Definition
 Most recalling, effected by extremes, simple, stable, appropriate
Term
 How is the mode estimated from ungrouped data?
Definition
 finding the most appropriate ungrouped data
Term
 How can you estimate the mode from a frequency distribution?
Definition
 Find high frequency class
Term
 How can you estimate the mode from a histogram?
Definition
 Perpendicular line, dotted arrow
Term
 Define median
Definition
 Center of distibution
Term
 Six characteristics of the median are:
Definition
 All values above or below any # unaffected, must order values first
Term
 How is the median calculated from ungrouped data when there is an odd number of values?
Definition
 After it is ordered, the middle number
Term
 How is the median calculated from ungrouped data when there is an even number of values?
Definition
 It's assumed 1/2 way between two values
Term
 When should you use the arithmetic mean?
Definition
 When you need equal emphasis on each figure
Term
 What is the mathematical definition of the arithmetic mean
Definition
 the point that the standard deviation = 0
Term
 What is the harmonic mean primarily used for?
Definition
 Averaging things, especially time
Term
 List five characteristics of the mean.
Definition
 Effected by extreams, dependant array. Interval ration sum of deviations from mean is zero sum of two to the power of s is less than all points
Term
 How is weight calculated when using the weighted arithmetic means?
Definition
 multiplying value by appropriate quantitative number
Term
 when would a harmonic mean be considered useless?
Definition
 If there are zeroes.
Term
 Define standard deviation in mathematical terms
Definition
 Square root of the squares
Term
 In the equations for calculating the standard deviation, what step gets rid of the negative values
Definition
 Square the deviation
Term
 In a population, if all the values are zero, what is the standard deviation?
Definition
 Zero
Term
 How are the standard deviation and the variance related?
Definition
 Deviation is the square root of variance
Term
 In a normal distribution, as n grows smaller, what happens to s?
Definition
 less representative of the population
Term
 Define the sampling distribution fo the mean
Definition
 theory distribution of means
Term
 The variability for the average of x values in the sampling distribution fo means is affected by what two factors?
Definition
 Size, how varied samples are
Term
 Define the standard error of the mean
Definition
 deviation of population divided by the square root of the sample size
Term
 The normal distribution is composed of what two parameters?
Definition
 Mean/standard deviation
Term
 Like all continuous distributions, the total area under the curve is what percentage?
Definition
 100%
Term
 For normality testing, what is the first step in plotting data?
Definition
 Arrange data low to high
Term
 What is a good method to learn to recognize normal data distributions?
Definition
 Plot skewed data, compare to known
Term
 What percentage of individual items are located within a distance of one standard deviation from the mean in a normal distribution?
Definition
 68.26%
Term
 What does the Z score represent?
Definition
 How many standard deviations from the mean
Term
 WHat is a symmetrical curve?
Definition
 Each half of the curve is equal to itself
Term
 What is a nonsymmetrical curve?
Definition
 The halves differ
Term
 what type of curve is very common when portraying the distribution of maintenance data
Definition
 positive skew
Term
 Which is the best example of a population in statistical language?a. yearly b1 failures at dyess afbb. weekly c-130 failures at scott afbc. monthly e3c failures at tinkerd. total t38 failures across the af
Definition
 D.
Term
 A sample of a population that is taken in such a manner that each value has an equal chance of being selected is referred to as a a. biased sampleb. random samplec. sampling theoryd. sampling application
Definition
 b. random sample
Term
 What are measures such as the mean or median called if they are computed from a sample?a. statisticsb. parameterc. populationd. distribution
Definition
 a.
Term
 Which measurement scale consists of equal intervals between scale values and an arbitrary zero point?a. ratiob. nominalc. ordinald. interval
Definition
 d. interval
Term
 The second step in making a frequency distribution is toa. determine the data's rangeb. determine the class interval sizec. range the data from largest to smallestd. range data from smallest to largest
Definition
 B
Term
 Given the following noncumulative frequency distribution, which class interval will give you 18 classes?a. .1b. .2c. .3d. .4
Definition
 c
Term
 If you construct a frequency distribution and the class interval is too large, the result isa. loss of detailb. side gaps between itemsc. overlapping lower limitsd. loss of smoothness and simplicity
Definition
 a.
Term
 When constructing a frequency polygon, what are plotted against the corresponding midpoints?a. series of rectanglesb. individual values of datac. lower limit and baselined. frequencies of the various class intervals
Definition
 d
Term
 Which graphical method gives the best representation of the number of individual values in each class?a. histogramb. frequency polygonc. overlapping polygond. overlapping histogram
Definition
 b
Term
 what measure of central tendancy is the mostt typical value in a distributiona. meanb. modec. mediand. weighted mean
Definition
 b
Term
 What is the mode of sampling consisting of these values: 6, 9, 10, 3, 2, 6, 25a. 2b. 6c. 8d. 18
Definition
 b
Term
 The median cannot be used with data from which measurement scale?a. nominalb. intervalc. ordinald. ratio
Definition
 a
Term
 Analysts frequently use the median because it is easy to compute and gives a better picture of data than the mean and mode when data area. skewedb. inconclusivec. normald. incomplete
Definition
 a.
Term
 What must you do first to determine the median from ungrouped data?a. arrange the data in classesb. determine the numerical averagec. determine the total of the valuesd. array the data in ascending order
Definition
 d
Term
 A true characteristic of the arithmetic mean it isa. affected by extreme valuesb. not usable with the ration measurement scalec. not affected by the number of items in the distributiond. the most frequently occuring value in the distribution
Definition
 a
Term
 What is the arithmetic mean of the values: 8, 10, 11, 11, 5?
Definition
 C
Term
 Compute a weighted mean for a distibution containing two values of 3 each, four values of 2 each, and 4 values of 5 each?a. 1b. 3.4c. 6.6d. 11.3
Definition
 b
Term
 For any distribution the sum of the deviations isa. oneb. zeroc. less than oned. more than one
Definition
 b
Term
 For a standard deviation of a population, if the number of values increases, the standard deviation.a. increasesb. decreasesc. formula changesd. remains the sam
Definition
 A
Term
 In a sample, you have 10 X values and each value is equal to 7. What is the standard deviation of the sample? a. 0b. 2.6c. 14d. 49
Definition
 A
Term
 As the number of values in a normal distribution sample decreases, the standard deviationa. becomes more representative of the populationb. becomes less representative of the populationc. remains the samed. increases
Definition
 B. becomes less representative of the population
Term
 Given a large number of random samples, how is the mean of all the sample means related to the population mean?a. it is the sameb. it is radically differentc. it is exactly 3 standard eviations apartd. it is more than three standard deviations apart
Definition
 a.
Term
 A normal distribution contains what two parameters?a. mean and modeb. standard error and modec. mean and standard deviationd. standard error and standard deviation
Definition
 c
Term
 In a normal distribution, 99 percent of the area under the normal area curve is contained within how many standard deviations on each side of the meana. 1b. 2c. 3 d. 4
Definition
 C
Term
 When plotted on normal probability graph paper, data from a normal distribution shows up as aa. circleb. curved linec. straight lined. bell shaped cuve
Definition
 c
Term
 How many standard deviations are represented by a value of 22 if the average of X is 14 and s is 5.a. -2.8b. -1.6c. 1.6d. 2.8
Definition
 c
Term
 If the average of X equals 24 and s equals 6, what are the values of the average of X plus or equal to 2sa. 24 and 48b. 18 and 36c. 12 and 36d. 12 and 24
Definition
 c
Term
 The variable that measures how many standard deviations a value is from the mean is thea. x scoreb. z scorec. standard deviationd. standard error of the mean
Definition
 b. z score
Term
 Where does the most frequent value of a normal curve occur?a. at the center of the distributionb. at all points in the distributionc. at the tail end of the distributiondd. away from the center of the distribution
Definition
 a
Term
 Define the method of variables?
Definition
 quantitative classification of data
Term
 describe the method of attributes?
Definition
 nonquantitative classification
Term
 define chance causes of variation
Definition
 inheirant in system
Term
 Define assignable causes of data
Definition
 you can attribute a cause, outside forces
Term
 Why do analysts use control charts?
Definition
 to find assignable causes
Term
 why is an investivation neccessary when points fall outside the established control limits on a control chart?
Definition
 to see if it is in or out of control
Term
 Explain why a process is out of control when seven consecutive points are on the same side of the centerline
Definition
 indicates result is not representative of population
Term
 what ristks are taken when you use control limits too close together on a control chart
Definition
 look for nonexistant issues
Term
 What should the analyst do when it has been decided that not enough time is being spent investivating assignable causes for variation?
Definition
 switch to tighter controls
Term
 What is the center line (CL) for the chart of individuals?
Definition
 mean
Term
 When a mean and standard deviation of a sample of past data are known, how are the upper and lower control limits determined for the chart of individuals
Definition
 Add or subtract one standard deviation
Term
 In what type of maintenance situation can the control chart for individuals be used?
Definition
 Repetitive, constant jobs
Term
 The control limits of the chart for individuals are based on what kind of sampling distribution?
Definition
 normal
Term
 How does the centerline of a chart for individuals compare with the centerline of a chart of averages?
Definition
 centerlines equal
Term
 What is the measure of variability of a chart for averages?
Definition
 standard error of the mean
Term
 what is the difference between the points plotted on a chart for individuals and the points plotted on a chart of averages?
Definition
 Plot on a chart-sample mean. Chart of individuals- individuals.
Term
 Name one advantage that a chart of averages has over a chart of individuals
Definition
 Averages remain mostly in control
Term
 Name one advantage that a chart of averages has over a chart of individuals
Definition
 Averages remain mostly in control
Term
 Compare the sampling distributions associated with a chart for individuals with the sampling distribution of a chart for averages
Definition
 both need normal distributions
Term
 What is the purpose of a chart for dispersion?
Definition
 measures changes in dispersion
Term
 WHich other control chart is used in conjunction with an R chart?
Definition
 average of X
Term
 How does subgroup or sample size affect the construction of the R chart?
Definition
 kept small to keep variations between groups
Term
 Why must the sample size never be changed for previously established average of X chart and Rcharts?
Definition
 control limits based on sample
Term
 Define the terms defect and defective
Definition
 Defect- discrepancy like PMCDefective- broken, NMC
Term
 What is the c chart designed for
Definition
 plot detedcted defects
Term
 What does the C chart have for its centerline
Definition
 average # of defects per sample
Term
 What condition must the sample size or unit inspected meet when using the C chart?
Definition
 Size needs to remain constant
Term
 The causes of variation that can be identified on a control chart, regulated, and possibly eliminated area. chanceb. naturalc. randomd. assignable
Definition
 d.
Term
 The purpose of a control chart in statistics is toa. identify causes for variationb. eliminate causes for variationc. detect the presence of chance causes for variationd. detect the presence of assignable causes for variation
Definition
 d.
Term
 In general statistical terms, a control chart tells youa. what the problem might bewhen to look for a problemwhere the root cause of a problem isd. how to correct and eliminate a problem
Definition
 b.
Term
 When identifying processes out of control and using a control chart, what action should you take if you have set your control limits at three standard deviations and suspected problems are falling within control limits?a. switch to tighter limitsb. recalculate to find standard deviationc. keep established limits and don't investigated. discard current data and recalculate standard deviation
Definition
 a.
Term
 In statistical terms, what does the control chart for plotting individual X values use for the center line?a. meanb. modec. standard deviationd. standard error of the mean
Definition
 a.
Term
 the statistical interpretation of a control chart for individuals would be distorted if the a. distribution is normalb. distribution is extremely skewedc. standard deviation too smalld. standard deviation too large
Definition
 b
Term
 In statistics, the control chart for averages is best used when dealing with data that isa. simpleb. complexc. in relatively small amountsd. in relatively large amounts
Definition
 d.
Term
 What characteristic of the distribution used in a control chart for averages gives it an advantage over chart of individuals?a. distribution of means always tends to be normalb. population must be normalc. population cannot be skewedd. individual samples arent used
Definition
 A
Term
 Which statistical chart measures changes in the means of a series?a. chart of individualsb. chart for averagesc. range chard. p chart
Definition
 b
Term
 What subgroup sample size is commonly used when constructing a statistical range chart?a. 4-5b.6-10c. 10-20d.20-25
Definition
 b
Term
 In statistics, what item on a p chart is affected by large changes in size?a. center lineb. control limitsc. standard deviationd.standard error of the mean
Definition
 b
Term
 In statistics, a c chart may be used to measurea. number of defective unitsb. number of defects per unitc. percent of defective units, percent of defects per squadrond. percent of defectives per units
Definition
 b
Term
 in statistics, a range chart is usually coupled with a a. c chartb. p chartc. chart of averagesd. chart of individuals
Definition
 c.
Term
 On what sttistical control chart is the number of defects per unit plotteda. c hartb. p chartc. chart of averagesd. chart of individuals
Definition
 A
Term
 Why can't detailed investigations be made on everything in maintenance?
Definition
 massive amount of data, limited time
Term
 WHat is the purpose of hypotheses testing in analysis?
Definition
 identify trends, differences, differences
Term
 How is null hypothesis denoted?
Definition
 H
Term
 Define alternate hypothesis?
Definition
 Hypothesis available if null is wrong
Term
 Why are sampling distributions used in hypothesis testing
Definition
 for making adds on the likelyhood of an occurance
Term
 When a given hypothesis is rejected, when in fact it is true, what type of error was made?
Definition
 Type 1
Term
 What is alpha?
Definition
 probability of a type 1 error
Term
 Define level of significance
Definition
 risk factor you're willing to accept
Term
 What is used to set up level of significance?
Definition
 assigns portions of data in normal curve as rejection area
Term
 list the six types of hypothesis testing procedures
Definition
 state type, choose test, set gigint,distro, compute, makes computer doo things
Term
 State an advantage of presetting the level of significance before making the comparason step in hypothesis testing.
Definition
 more objective, less doubt
Term
 What step in hypotesis testing normally takes longer to perform? why?
Definition
 compute, many calculations
Term
 Which factor of hypothesis testing determines the level of confidence in your decision?
Definition
 significance
Term
 Define parametric and nonparametric tests
Definition
 parametric- strong, basic assumptions. Nonparametric- less rigid, no assumptions
Term
 Which type of statistical test uses data from a normal distribution?
Definition
 parametric
Term
 Parametric tests use which measurement scales?
Definition
 Interval/ratio
Term
 Nonparametric tests use data from which measurement scales?
Definition
 NOIR' Nominal, Ordinal, Interval, Ratio
Term
 List five assumptions and tests neccessary to compare the means of two samples of size 40.
Definition
 Independant/random, ratio/oridnal, continuous/normal distrobution, homovariance performed
Term
 What measurement scale is required before a mann-whitney u test can be performed?
Definition
 ordinal
Term
 Which tests can be used with a nominal scale?
Definition
 chi-square
Term
 What do you use to determine if your sample differences are within the extreme regions in the sampling distribution?
Definition
 critical values.
Term
 What six questions must you answer to go through the proper sequence of statistical tests?
Definition
 discrete or continuous? nominal? outliers?
Term
 what is the purpose of a T test?
Definition
 test extreme values to determine outliers
Term
 What is the first step in determining if an outlier exists in a data series
Definition
 plot data on graph paper
Term
 What action should be taken from the T test statistic is > T critical value?
Definition
 eliminated from further computation
Term
 What does the F test accomplish for the analyst?
Definition
 Determines significant differences between variances
Term
 What is the df value for a sample size of 24?
Definition
 23
Term
 What is the indication when you state a null hypothesis and the F test statistic is
Definition
 not significantly different
Term
 Whta table of probability is used with the z test for means?
Definition
 normal curve
Term
 How are the two samples treated when assigning ranks for computing a U test tatistic
Definition
 as one sample size
Term
 You computed two U values. Which U value do you select as the U test statistic
Definition
 smaller
Term
 To use an H test, the data must come from at least which measurement scale?
Definition
 ordinal
Term
 What effect will value ties across samples have on the H test?
Definition
 excessive ties weaken test
Term
 What sampling distribution test do you use when more than three samples are used with the H test.
Definition
 Chi squared
Term
 State the purpose of an x to the second power test
Definition
 To test if major differences exist between frequencies in categories
Term
 What is the minimum of expected frequencies when using the x to the second power test?
Definition
 5. Not less than one
Term
 How is E determined when only one sample is used in a x to the second power test?
Definition
 E=sum of the population/K
Term
 What is the indication when the x to the second power test statistic is less than the x to the second power value using H to the 0?
Definition
 significant differences
Term
 The various statistical techniques associated with hypothesis testing should be performeda. neither very large nor very smallb. either very large or very smallc. very smalld. very large
Definition
 a
Term
 Hypothesis testing is used in data analysis tocalculate linear trendscalculate probabilitesidentify differences of the meansidentify significant differances, trends, and relationships
Definition
 D
Term
 What type of hypothesis assumes no significant difference between two or more population samples?a. alternateb. directionalc. null or givend. directional alternate
Definition
 c
Term
 How would you state the null hypothesis concerning your assumption between population A and pop B? The mean population of Aa. is equal to the mean of pop Bb. is less than the mean of pop Bc. is greater than the mean of pop Bd. cannot be measured with the mean of pop B
Definition
 A
Term
 The probability of making a type I statistical error is denoted bya. betab. muc. alphad. rho
Definition
 c. alpha
Term
 When you assign a level of significance to a statistical test, you are actually assigninga. a certain proportion of data in the normal curve area as your acceptance regionb. certain proportion of data in the normal area curve as your rejectionc. standard errror of the mean as your rejection regiond. the standard deviation as your cutoff point
Definition
 b
Term
 What is the first step in the hypothesis testing procedure?a. determine sampling distributionb. state two hypothesisc. compute statisticd. choose tests
Definition
 b
Term
 What statistical test makes no assumptions about the shape of the populations from which the samples come?a. parametricb. directionalc. nondirectionald. nonparametric
Definition
 d
Term
 In statistical testing, the extreme regions in sampling distributions are signified bya. critical valuesb chi squaresc. null valuesd variances
Definition
 a
Term
 In parametric testing, a t test is a one tailed test becausea. only one factor is usedb. only one tail of the sampling distro is usedc. both tails are used togetherd. one tail is subtracted from the other
Definition
 b
Term
 If you use an f test for variance between two samples, you will reject your null hypothesis when
Definition
 a. greater than the F critical valueb. less than F criticalc. negative valued. zero
Term
 In statistics, a t test evaluates the significance of the difference between thea. variance of more than two large samplesb. variance of two small samplesc. means of two small samplesd. means of two large samples
Definition
 C
Term
 For a t test, what should the sample size be for differences between sample means?a. less than 10b. less than 30c. larger than 30d. larger than 50
Definition
 B
Term
 For a z test, the sample size for differences between sample means should a test a 10b. 20c. 30d. 40
Definition
 C
Term
 In nonparametric testing when making a comparison to the table of U critical values, you use thea. differrnce of the u statisticb. sum of the u statisticc. smaller u statisticd. larger u statistic
Definition
 c
Term
 In nonparametric testing, why is the U test statistic converted to a z deviate when the sample size is no greater than 20?a. no table exists for the comparing u statisticsb. z deviates are easier than u statisticsc. the u statistic can be compared to the table of u critical valuesd. the sampling distribution of U rapidly approaches the normal distribution
Definition
 D
Term
 The Kruskal-wallis H test requires data from at least what scale?a. ratiob. intervalc. ordinald. nominal
Definition
 C
Term
 In nonparametric testing, what number of samples can the x 2 test be used for?a. only one sampleb. no more than two samplesc. three to five samplesd. any number of samples
Definition
 D
Term
 In a nonparametric testing, what is the degree of freedom for a x 2 sample containing FIVE categories and FOUR rows in a multi sample test?
Definition
 A
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