CH.3 TERMS

Question 1

measures computed for data from a sample

Answer 1

Sample statistics

Question 2

measures computed for data from a population

Answer 2

population parameter

Question 3

a sample statistic of the corresponding population parameter

Answer 3

point estimator

Question 4

average value for a variable

Answer 4

mean

Question 5

value in the middle when the data items are arranged in ascending order

Answer 5

median

Question 6

value that occurs with the greatest frequency

Answer 6

mode

Question 7

how the data are spread over the interval from the smallest value to the largest value

Answer 7

percentile

Question 8

specific percentiles

Answer 8

quartile

Question 9

the difference between the largest and the smallest values

Answer 9

range

Question 10

difference between the third quartile and the first quartile

Answer 10

interquartile range

Question 11

average of the squared differences between each data value and the mean

Answer 11

variance

Question 12

positive square root of the variance

Answer 12

standard deviation

Question 13

measures the standard deviation relative to the mean

Answer 13

coefficient of variation

Question 14

measures the shape of the distribution

Answer 14

skewness

Question 15

standard value denotes the number of standard deviations of a data values xi is from the mean

Answer 15

z-score

Question 16

if the distribution is roughly bell shaped then 68% is 1 SD of the mean, 95% is 2 SD of the mean, and 99.7% is 3 SD of the mean

Answer 16

empirical rule

Question 17

observations with unusually large or small values

Answer 17

outlier

Question 18

smallest value, first quartile, median, third quartile, and largest value are used to summarize data

Answer 18

five number summary

Question 19

graphical summary of data based on five number summary

Answer 19

box plot

Question 20

measure of the linear association between two variables, positive or negative

Answer 20

covariance

Question 21

measures the relationship between two variables. Not affected by the units of measurement for x and y

Answer 21

correlation coefficient

Question 22

mean is computed by giving each data value a weight that reflects its importance

Answer 22

weighted mean