Chapter 4

Question 1

mode

Answer 1

the most frequently occurring observation in the data set

Question 2

median

Answer 2

the observation at the center of the distribution so that 50% of the observations in the set are below it and 50% are above it

Question 3

mean

Answer 3

the arithmetic average of a set of observations obtained by summing the observations in the set and dividing that sum by the number of observations in the set

Question 4

outlier

Answer 4

an observation in a data set that is much larger or smaller than most other scores in the distribution

Question 5

negatively skewed distribution

Answer 5

a non-normal distribution where most observations have high values and the outliers have low values; a distribution with a long left-hand tail, where the mean is less than the median and the mode

Question 6

positively skewed distribution

Answer 6

a non-normal distribution where most observations have low values and the outliers have high values; a distribution with a long right-hand tail, where the mean is greater than the median and the mode

Question 7

normal distribution

Answer 7

a distribution that is bell-shaped and symmetrical about the mean; a distribution where the mean, median, and mode all have the same value