Chapter 3

Question 1

abscissa

Answer 1

horizontal axis on a histogram, representing different values of x

Question 2

ordinate

Answer 2

density, vertical axis on a histogram, related to the frequency of the occurrence of x

Question 3

standard normal distribution

Answer 3

mean of 0 and standard deviation of 1

Question 4

pivotal quantity

Answer 4

z, distribution will always be normal regardless of values of 2 parameters

Question 5

deviation scores

Answer 5

measure deviations from the mean

Question 6

z scores

Answer 6

represents the number of standard deviations that Xi is above or below the mean (positive scores lie above the mean, and negative scores lie below the mean)

Question 7

prediction interval

Answer 7

when the population mean is known and we are trying to predict where a single observation (X) will fall

Question 8

Q-Q plots

Answer 8

quantile-quantile plots, for determining if a set of data is normally distributed better than superimposing a normal curve on a histogram

Question 9

Kolmogorov-Smirnov test

Answer 9

best-known statistical test for normalcy, weak test that should not be used

Question 10

standard scores

Answer 10

distribution with mean of 0 and standard deviation and variance of 1, like IQ

Question 11

percentile

Answer 11

the percentage of scores that fall below the individual’s score (for example, 91 percentile means that 91% of test scores fall below this person’s test scores)

Question 12

T score

Answer 12

mean of 50 and standard deviation of 10, useful in psychological measurement b/c of standard frame of reference