In a positively skewed distribution, which measure of variation (mean, median, mode) is most likely to be largest?

We are interested in the amount of sleep university students get. We take a random sample of six students and inquire how much sleep they got last night. The data are shown in the table. What is the range?

i sleep time

1 3

2 8

3 2

4 8

5 4

6 5

In the distribution of GRE scores ( = 150, = 10), approximately what is the percentile rank of a GRE score of 165?

We are interested in the amount of sleep university students get. We take a random sample of six students and inquire how much sleep they got last night. The data are shown in the table. What is the variance?

i sleep time

1 3

2 8

3 2

4 8

5 4

6 5

The mode, median, and mean of a unimodal distribution were 8, 6, and 4, respectively. This distribution is _____ skewed.

True/False The sum of the deviations in a distribution is always equal to +1.00.

The percentage of scores equal to or less than a given score is called a ___.

True/False The relative area of the normal curve between the mean and one standard deviation above it will change as the values of and change.

True/False All normal distributions have the same mean and standard deviation.

True/False The range is easily defined for a normal distribution.

True/False If a score is the 35th percentile, then 35% of all the scores in the reference group are equal to or less than the given score.

True/False The mode can be used only with nominal data.

True/False If data are interval/ratio, only the range can be used as a measure of variation.

True/False The mean is computed by dividing the total number of entries in a data set by the sum of the entries.

True/False If the units of the original data are seconds, the units of the standard deviation are also seconds.

True/False Measures of central tendency are used to specify the width of a distribution.

True/False Measures of variation describe where the center of a distribution is.