Question

The mean playing time for a large collection of compact discs is 37 minutes, and the standard deviation is 4 minutes.

(a)

What value (in minutes) is 1 standard deviation above the mean? One standard deviation below the mean? What values are 2 standard deviations away from the mean?

1 standard deviation above the mean  

1 standard deviation below the mean  

2 standard deviations above the mean  

2 standard deviations below the mean

(b)

Assuming that the distribution of times is mound-shaped and approximately symmetric,

approximately what percentage of times are between 29 and 45 minutes? (Hint: See Example 3.19. Use the Empirical Rule.)

  

Less than 25 min or greater than 49 min?

Less than 25 min?

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2)

Data on weekday exercise time for 20 females, consistent with summary quantities given in the paper "An Ecological Momentary Assessment of the Physical Activity and Sedentary Behavior Patterns of University Students,"† are shown below.

Female—Weekday

10.0	90.6	48.5	50.4	57.4	99.6	0.0	5.0	0.0	0.0
5.0	2.0	10.5	5.0	47.0	0.0	5.0	54.0	0.0	48.6

Calculate the values of the median and interquartile range.

median interquartile range

Interpret the values of the median and interquartile range.

The median exercise time of indicates that half of the exercise times were below, and the remaining half were above. The interquartile range tells us that the middle fifty percent of exercise times had a range of.

Answer 1