# Measures of depersions

CJ 301

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Assignment # 4 – Measures of Dispersion

In order to complete this assignment please read the lecture: Measures of Dispersion under the Learning Modules. (RANGE, MEAN DEVIATION, VARIANCE, STANDARD DEVIATION).

Due date: February 15, Sunday (by midnight)

*20 points total

NAME: _______________________________________________________________

A random sample of five convicts received the follow prison sentences (in years): 3 points

3          7          3          2          10

Find the mode.

Find the median.

Find the mean.

What are the four different measures of dispersion? 1 point

3. Why is the range the most convenient measure of dispersion, yet the most imprecise measure of variability? When would you use the range? 1 point

What is (are) the difference between measures of central tendency and measures of dispersion? 1 points

5. A study based on a sample of 9 students yields the following scores on a 10-point scale of cultural diversity awareness. 5 points

2      6       8       7       1       2       7       2       3

What is the mean?

What is the median?

What is the mode?

What is the standard deviation?

The parole board is alarmed by the low number of years actually spent in prison for those inmates sentenced to 20-year sentences. To help them make parole recommendations they gather data on the number of years served for a sample of 5 potential parolees. The number of years served for these 5 parolees is as follows:

2

6

7

4

7

Question: What is the standard deviation?  4 points

What is the standard deviation for the following distribution : 4 points

2

8

5

4

5

A university professor was interested in identifying left-handed students from all of the six introductory-level psychology classes in the department. The number of left-handed students in each class is: 33, 6, 22, 3, 2, 1. What is the range? 1 point