A useful measure to compare the relative dispersion of two or more distributions, if they are in different units, is the coefficient of variation.
The scores from a state standardized test have a mean of 80 and a standard deviation of 10. The distribution of the scores is roughly bell-shaped. Use the Empirical Rule to find the percentage of scores that lie between 60 and 80.
In distributions that are skewed to the left, the relationship of the mean, median, and mode is mode < median < mean.
The smaller the spread of scores around the arithmetic mean, the smaller the standard deviation.
The test scores of a 9th grade history test were recently collected for 20 students. The data is as follows: 62, 64, 68, 70, 73, 76, 77, 78, 79, 81, 82, 85, 85, 85, 88, 89, 91, 94, 96, 97. The interquartile range is 15.
Which of the following descriptive statistics is NOT measured in the same units as the data? The interquartile range.
Suppose annual salaries for sales associates from Hayley's Heirlooms have a bell-shaped distribution with a mean of $32,500 and a standard deviation of $2,500. The z-score for a sales associate from this store who earns $37,500 is 2.
Which measure of central tendency can be used for both numerical and categorical variables? None of the above can be used for both numerical and categorical variables.