# Shared Flashcard Set

## Details

Exam 1
Terms
87
02/11/2014

Term
 Descriptive
Definition
 Summarizes the values of a data set by using charts and graphs, averages, and tables
Term
 Inferential
Definition
 Make generalizations based on the descriptive stats of our sample
Term
 Population
Definition
 Entire group of people or objects to be studied.
Term
 Process
Definition
 Activities that turn inputs into outcomes
Term
 Sample
Definition
 Subset of population
Term
 Parameter
Definition
 VALUE that summarizes a characteristic of a POPULATION
Term
 Statistic
Definition
 VALUE that summarizes a chacteristic of a SAMPLE
Term
 Sampling Error
Definition
 Difference between the result of a sample and census
Term
 Statistical Inference
Definition
 Using sample information to learn about a population
Term
 Statistical Variable
Definition
 Single Charactersistic of any object or event
Term
 Qualitative Data
Definition
 Data expressed in words usually
Term
 Nominal DAta
Definition
 Data units are placed in classes and have no natural ordering
Term
 Example of nominal data
Definition
 PSU ID, car color
Term
 Ordinal Data
Definition
 Data units are ranked in some sort of order
Term
 Example of Ordinal Data
Definition
 Hotel ratings, class standing.
Term
 Quantitative data
Definition
 Data values are measured by meaningful numbers that tell how much or how many
Term
 Interval Scale
Definition
 no defined zero value, ratio is not meaningful, Valid Computation: Difference
Term
 Example of Interval Scale
Definition
 Cloth sizes, temperature
Term
 Ratio Scale
Definition
 Defined zero value, ratio is meaningful, Vaid computation: difference or average
Term
 Example of RAtio scale
Definition
 Prices, distances
Term
 TRue or False: A desciptive measure of a sample is a parameter
Definition
 False: Its a statistic
Term
 True or False: We should determine our objective before we start collecting data
Definition
 True
Term
 True or False: The numbers on a jersey is qualitative data
Definition
 True
Term
 Distribution
Definition
 The way that observations are spread across a range of values
Term
 Frequency Table
Definition
 A table that tabulates the number of times a variable occurs
Term
 Bar Chart
Definition
 A graph of QUALITATIVE DATA. Frequencies on vertical axes, classes on horozontal.
Term
 Relative Frquency
Definition
 Frequency compared to the total. always a %
Term
 Bin
Definition
 A frequency table group that covers a particular range of values.
Term
 Histogram
Definition
 Bar graph of quantitative data in which each bar represents a bin. The height of the bar is proportional to the number of data values in the bin.
Term
 Why do we have to define bin categories?
Definition
 So we dont hdouble count data
Term
 A cumulative Relative Frequency always totals too:
Definition
 100%
Term
 Skewed Left
Definition
 Negative, values clustered on right
Term
 Skewed Right
Definition
 Postitive, values clustered on left
Term
 True or false A data set that is skewed left has most of the data values on the lft with a few trailing off to the right
Definition
 False: that would be skewed right
Term
 Why is a stem and leaf plot useful?
Definition
 Shows distribution of data AND contains all the original data values.
Term
 What information can we get from a stem and leaf plot?
Definition
 Min value, Max value, Median, Mode
Term
 Percentile
Definition
 VALUES in a data set that divide the data into 100 equal parts.
Term
 Quartiles
Definition
 Located at the 25th, 50th, and 75th percentiles
Term
 Interquartile Range
Definition
 DIFFERENCE between first and third quartiles (central 50% of data)
Term
 Boxplot
Definition
 A pictorial display that indicates the range, median, and interquartile range
Term
 True or False:  The first quartile of a disribution can never be less than zero
Definition
 False: a value can be negative
Term
 True or False: A boxplot is a good way to show the mean of a data set
Definition
 False: Doesnt directly show the mean
Term
 True or False: A stem and leaf plot cannot be constructed from a boxplot, but a boxplot can be constructed from a stem and leaf plot
Definition
 True: Stem and leaf has data values
Term
 Mean
Definition
 Sum of all numerical observations/ total number of observations
Term
 Median
Definition
 Middle value in an ordered array of numbers (50th Percentile)
Term
 Absolute Measure
Definition
 Has Data Units
Term
 Relative Measure
Definition
 Has No Units (Independent of data)
Term
Definition
 Easy to understand, easy to compute, uses all data values
Term
Definition
 Affected by Outliers, Cant compute it for open-ended frequency distributions
Term
 True or False: The median and mode are not affected by outliers
Definition
 TRue: only mean
Term
 True or False: Every data set has a mode
Definition
 False
Term
 Uniform
Definition
 Each of the values are occuring at the same times
Term
 Measures of variability
Definition
 Mean absolute deviation Standard Deviation Variance Coeffiecient of variation
Term
 How to find variance
Definition
 FInd Mean Subtract each value from mean Square those numbers Then add them together and divide by number of of values   For a sample: subtract number of values by 1
Term
 How to find Standard deviation
Definition
 Square root of variance
Term
 Finding Mean absolute deviation
Definition
 Find Mean Subtract each value by mean Take absolute value of answers and add together Divide by number of values
Term
 Which measures of variation measure distance from mean?
Definition
Term
 True or false: Median is a measure of variablity of a data set
Definition
 False
Term
 Range is sensitive to all data values TRue or False
Definition
 False, only to the highest and lowest values
Term
 True or False: If we want the average of all the deviations from the mean of a data set, we can simply divide by n
Definition
 False, we would get 0
Term
 Standard Deviation measures varitaion
Definition
 Fluctuation, Riskiness, Reliability, Volatility, measurement Error, Sampling Error
Term
 True or False: A standard deviation can sometimes be larger in numerical value than a variance
Definition
 True
Term
 Coefficent of Variation
Definition
 standard deviation/ mean of distribution times 100
Term
 Empiracal Rule
Definition
 68% of the data values lie within one standard deviation of the mean 95% of the data values lie within 2 standard deviations of the mean 99.7% of the data values lie within 3 standard deviations of the mean
Term
 Standard Score
Definition
 Student Score- Mean score/ Standard Deviation
Term
 Probability
Definition
 Goes from general to the specific
Term
 Inference
Definition
 Goes from the specific to the general
Term
 Random Experiment
Definition
 process of obtaining info from data collected from a study that has unpredictable outcomes
Term
 Simple Events
Definition
 the most basic possible outcomes of an experiment that cannot be broken down an further
Term
 sample space
Definition
 collection of all possible simple events
Term
 event
Definition
 subset of sample space
Term
 Mutually Exclusive  Events
Definition
 Both events cannot occur at the same time
Term
 Complementary Events
Definition
 A 2nd event made up of all simple events not in that first event. These 2 events make up entire sample space
Term
 THe items in a sample space must be...
Definition
 Exhaustive
Term
 Theoritcal Approach
Definition
 # of possible ways of obtaining and event/ # of replications
Term
 Relative Frequency
Definition
 most common approach # of times event occurs/ # of replications
Term
 Subjective Judgement
Definition
 - conditions cannot be replicated - Probability represents an individuals judgement
Term
 True or False: When a probabilty is desrcibed in terms of the proportion of times that an event can be theoretically expected to occur, it is an example of relative frequency.
Definition
 FALSE
Term
 True or False: When one throws a die 1000 times and determines that the probability of obtaining a six on a die is 1/6 that person has used the theoretical approach to probability
Definition
 False
Term
 Discrete Probability Distribution
Definition
 Consists of whole numbers or values that have distance between them and are countable
Term
 COntinuos Probability Distribution
Definition
 Theoretically an infinite number of outcomes within a range
Term
 Requirements for a discrete
Definition
 The probability of each event must range from 0-1 The sum of probabilities must equal 1
Term
 True or False:  Distribution of peoples heights is an example of a discrete probability distribution
Definition
 False
Term
 True or False: The sum of the probabilities in a discrete probability distribution could total 1.2
Definition
 False: has to equal 1
Term
 Requirements for random variables:
Definition
 Numerical Values Probabilities associated with those values dont need to be equal
Term
 Expected Value
Definition
 Mean of X
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