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

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


Term
What is a good rounding rule? 

Definition
round only the final answer 


Term
How is the rate determined? 

Definition


Term
How is portion determined? 

Definition


Term

Definition


Term
What statistical method is considered objective, subjective? 

Definition
Descriptive and Inferential 


Term
In the function M=F(N) which is independant? Dependant? 

Definition


Term

Definition
to differentiate variables in a series 


Term
What is the meaning of the symbol Sigma? (backwards Eish) 

Definition
sum of all aforementioned figures 


Term
What is the value of 2 to the 5th power equal? Which is base? Exponet? 

Definition


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


Term
What is the value of 5/2*6? a. 0.3 b. 8.4 c. 15 d. 30 

Definition


Term
Compute the difference of the signed numbers: 17(10) a. 3 b. 3 c. 7 d. 27 

Definition


Term
Eighty is 40% of what number
A. 200 b. 820 c 400 d 500 

Definition


Term
what statistical method uses only a sample of data? a inferential b descriptive c data survey d randomization 

Definition


Term
Which action would require the use of the descriptive statistics method a. draw a conclusion about data b. chose a random sample of data c. summarize a large amount of data d. generalize from the results of small samples 

Definition


Term
In the equation Y=X+2 what does Y represent? a. exponet b. inequality c. subscript d. variable 

Definition


Term
What is the value of 4 to the 3rd power 

Definition


Term
What do you call data that can be expressed only in whole number units? 

Definition


Term
What is the meaning of "population" as used in statistical language 

Definition
the body from which the population was drawn 


Term

Definition
limits or barriers of a population 


Term

Definition
Splinter of the whole, chosen to represent a population 


Term

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


Term
Name two measurement scales that are non quantitative 

Definition


Term
What is the function of a frequency distrobution? 

Definition


Term
What is the first step in making a frequency distribution? 

Definition


Term
What is the reccomended number of classes in a frequency distribution? 

Definition


Term
What happens to a frequency distribution if the class interval is too small? 

Definition


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


Term
Which graphic representation gives a better idea of the general shape of a distribution? 

Definition


Term

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

Definition


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


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


Term
In a population, if all the values are zero, what is the standard deviation? 

Definition


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


Term
Like all continuous distributions, the total area under the curve is what percentage? 

Definition


Term
For normality testing, what is the first step in plotting data? 

Definition


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


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


Term
what type of curve is very common when portraying the distribution of maintenance data 

Definition


Term
Which is the best example of a population in statistical language? a. yearly b1 failures at dyess afb b. weekly c130 failures at scott afb c. monthly e3c failures at tinker d. total t38 failures across the af 

Definition


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 sample b. random sample c. sampling theory d. sampling application 

Definition


Term
What are measures such as the mean or median called if they are computed from a sample? a. statistics b. parameter c. population d. distribution 

Definition


Term
Which measurement scale consists of equal intervals between scale values and an arbitrary zero point? a. ratio b. nominal c. ordinal d. interval 

Definition


Term
The second step in making a frequency distribution is to a. determine the data's range b. determine the class interval size c. range the data from largest to smallest d. range data from smallest to largest 

Definition


Term
Given the following noncumulative frequency distribution, which class interval will give you 18 classes? a. .1 b. .2 c. .3 d. .4 

Definition


Term
If you construct a frequency distribution and the class interval is too large, the result is a. loss of detail b. side gaps between items c. overlapping lower limits d. loss of smoothness and simplicity 

Definition


Term
When constructing a frequency polygon, what are plotted against the corresponding midpoints? a. series of rectangles b. individual values of data c. lower limit and baseline d. frequencies of the various class intervals 

Definition


Term
Which graphical method gives the best representation of the number of individual values in each class? a. histogram b. frequency polygon c. overlapping polygon d. overlapping histogram 

Definition


Term
what measure of central tendancy is the mostt typical value in a distribution
a. mean b. mode c. median d. weighted mean 

Definition


Term
What is the mode of sampling consisting of these values: 6, 9, 10, 3, 2, 6, 25
a. 2 b. 6 c. 8 d. 18 

Definition


Term
The median cannot be used with data from which measurement scale?
a. nominal b. interval c. ordinal d. ratio 

Definition


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 are
a. skewed b. inconclusive c. normal d. incomplete 

Definition


Term
What must you do first to determine the median from ungrouped data? a. arrange the data in classes b. determine the numerical average c. determine the total of the values d. array the data in ascending order 

Definition


Term
A true characteristic of the arithmetic mean it is a. affected by extreme values b. not usable with the ration measurement scale c. not affected by the number of items in the distribution d. the most frequently occuring value in the distribution 

Definition


Term
What is the arithmetic mean of the values: 8, 10, 11, 11, 5? 

Definition


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. 1 b. 3.4 c. 6.6 d. 11.3 

Definition


Term
For any distribution the sum of the deviations is a. one b. zero c. less than one d. more than one 

Definition


Term
For a standard deviation of a population, if the number of values increases, the standard deviation. a. increases b. decreases c. formula changes d. remains the sam 

Definition


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. 0 b. 2.6 c. 14 d. 49 

Definition


Term
As the number of values in a normal distribution sample decreases, the standard deviation
a. becomes more representative of the population b. becomes less representative of the population c. remains the same d. 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 same b. it is radically different c. it is exactly 3 standard eviations apart d. it is more than three standard deviations apart 

Definition


Term
A normal distribution contains what two parameters?
a. mean and mode b. standard error and mode c. mean and standard deviation d. standard error and standard deviation 

Definition


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 mean a. 1 b. 2 c. 3 d. 4 

Definition


Term
When plotted on normal probability graph paper, data from a normal distribution shows up as a a. circle b. curved line c. straight line d. bell shaped cuve 

Definition


Term
How many standard deviations are represented by a value of 22 if the average of X is 14 and s is 5.
a. 2.8 b. 1.6 c. 1.6 d. 2.8 

Definition


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 2s
a. 24 and 48 b. 18 and 36 c. 12 and 36 d. 12 and 24 

Definition


Term
The variable that measures how many standard deviations a value is from the mean is the
a. x score b. z score c. standard deviation d. standard error of the mean 

Definition


Term
Where does the most frequent value of a normal curve occur?
a. at the center of the distribution b. at all points in the distribution c. at the tail end of the distributiond d. away from the center of the distribution 

Definition


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


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


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


Term
How does the centerline of a chart for individuals compare with the centerline of a chart of averages? 

Definition


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 chartsample 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


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 PMC Defective broken, NMC 


Term
What is the c chart designed for 

Definition


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 are a. chance b. natural c. random d. assignable 

Definition


Term
The purpose of a control chart in statistics is to a. identify causes for variation b. eliminate causes for variation c. detect the presence of chance causes for variation d. detect the presence of assignable causes for variation 

Definition


Term
In general statistical terms, a control chart tells you
a. what the problem might be when to look for a problem where the root cause of a problem is d. how to correct and eliminate a problem 

Definition


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 limits b. recalculate to find standard deviation c. keep established limits and don't investigate d. discard current data and recalculate standard deviation 

Definition


Term
In statistical terms, what does the control chart for plotting individual X values use for the center line? a. mean b. mode c. standard deviation d. standard error of the mean 

Definition


Term
the statistical interpretation of a control chart for individuals would be distorted if the a. distribution is normal b. distribution is extremely skewed c. standard deviation too small d. standard deviation too large 

Definition


Term
In statistics, the control chart for averages is best used when dealing with data that is
a. simple b. complex c. in relatively small amounts d. in relatively large amounts 

Definition


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 normal b. population must be normal c. population cannot be skewed d. individual samples arent used 

Definition


Term
Which statistical chart measures changes in the means of a series?
a. chart of individuals b. chart for averages c. range char d. p chart 

Definition


Term
What subgroup sample size is commonly used when constructing a statistical range chart? a. 45 b.610 c. 1020 d.2025 

Definition


Term
In statistics, what item on a p chart is affected by large changes in size? a. center line b. control limits c. standard deviationd .standard error of the mean 

Definition


Term
In statistics, a c chart may be used to measure a. number of defective units b. number of defects per unit c. percent of defective units, percent of defects per squadron d. percent of defectives per units 

Definition


Term
in statistics, a range chart is usually coupled with a a. c chart b. p chart c. chart of averages d. chart of individuals 

Definition


Term
On what sttistical control chart is the number of defects per unit plotted a. c hart b. p chart c. chart of averages d. chart of individuals 

Definition


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


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


Term

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


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


Term
Parametric tests use which measurement scales? 

Definition


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 mannwhitney u test can be performed? 

Definition


Term
Which tests can be used with a nominal scale? 

Definition


Term
What do you use to determine if your sample differences are within the extreme regions in the sampling distribution? 

Definition


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


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


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


Term
How are the two samples treated when assigning ranks for computing a U test tatistic 

Definition


Term
You computed two U values. Which U value do you select as the U test statistic 

Definition


Term
To use an H test, the data must come from at least which measurement scale? 

Definition


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


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


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


Term
The various statistical techniques associated with hypothesis testing should be performed a. neither very large nor very small b. either very large or very small c. very small d. very large 

Definition


Term
Hypothesis testing is used in data analysis to
calculate linear trends calculate probabilites identify differences of the means identify significant differances, trends, and relationships 

Definition


Term
What type of hypothesis assumes no significant difference between two or more population samples?
a. alternate b. directional c. null or given d. directional alternate 

Definition


Term
How would you state the null hypothesis concerning your assumption between population A and pop B? The mean population of A
a. is equal to the mean of pop B b. is less than the mean of pop B c. is greater than the mean of pop B d. cannot be measured with the mean of pop B 

Definition


Term
The probability of making a type I statistical error is denoted by
a. beta b. mu c. alpha d. rho 

Definition


Term
When you assign a level of significance to a statistical test, you are actually assigning
a. a certain proportion of data in the normal curve area as your acceptance region b. certain proportion of data in the normal area curve as your rejection c. standard errror of the mean as your rejection region d. the standard deviation as your cutoff point 

Definition


Term
What is the first step in the hypothesis testing procedure?
a. determine sampling distribution b. state two hypothesis c. compute statistic d. choose tests 

Definition


Term
What statistical test makes no assumptions about the shape of the populations from which the samples come?
a. parametric b. directional c. nondirectional d. nonparametric 

Definition


Term
In statistical testing, the extreme regions in sampling distributions are signified by
a. critical values b chi squares c. null values d variances 

Definition


Term
In parametric testing, a t test is a one tailed test because a. only one factor is used b. only one tail of the sampling distro is used c. both tails are used together d. one tail is subtracted from the other 

Definition


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 value b. less than F critical c. negative value d. zero 


Term
In statistics, a t test evaluates the significance of the difference between the
a. variance of more than two large samples b. variance of two small samples c. means of two small samples d. means of two large samples 

Definition


Term
For a t test, what should the sample size be for differences between sample means?
a. less than 10 b. less than 30 c. larger than 30 d. larger than 50 

Definition


Term
For a z test, the sample size for differences between sample means should a test a 10 b. 20 c. 30 d. 40 

Definition


Term
In nonparametric testing when making a comparison to the table of U critical values, you use the
a. differrnce of the u statistic b. sum of the u statistic c. smaller u statistic d. larger u statistic 

Definition


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 statistics b. z deviates are easier than u statistics c. the u statistic can be compared to the table of u critical values d. the sampling distribution of U rapidly approaches the normal distribution 

Definition


Term
The Kruskalwallis H test requires data from at least what scale?
a. ratio b. interval c. ordinal d. nominal 

Definition


Term
In nonparametric testing, what number of samples can the x 2 test be used for? a. only one sample b. no more than two samples c. three to five samples d. any number of samples 

Definition


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

