Re: Business Analysis Problems

Chapter 3

Descriptive Statistics: Numerical Measures

Learning Objectives

1. Understand the purpose of measures of location.

2. Be able to compute the mean, median, mode, quartiles, and various percentiles.

3. Understand the purpose of measures of variability.

4. Be able to compute the range, interquartile range, variance, standard deviation, and coefficient of variation.

5. Understand skewness as a measure of the shape of a data distribution. Learn how to recognize when a data distribution is negatively skewed, roughly symmetric, and positively skewed.

6. Understand how z scores are computed and how they are used as a measure of relative location of a data value.

7. Know how Chebyshev’s theorem and the empirical rule can be used to determine the percentage of the data within a specified number of standard deviations from the mean.

8. Learn how to construct a 5-number summary and a box plot.

9. Be able to compute and interpret covariance and correlation as measures of association between two variables.

10. Be able to compute a weighted mean.

Solutions:

1. [pic]

10, 12, 16, 17, 20

Median = 16 (middle value)

2. [pic]

10, 12, 16, 17, 20, 21

Median =[pic]

3. 15, 20, 25, 25, 27, 28, 30, 34

[pic] 2nd position = 20

[pic] [pic]

[pic] 6th position = 28

[pic] [pic]

4. [pic]

Median = 57 6th item

Mode = 53 It appears 3 times

5. a. [pic]

b. Median 10th $160 Los Angeles

11th $162 Seattle

Median =[pic]

c. Mode = $167 San Francisco and New Orleans

d. [pic]

5th $134

6th $139

[pic]

e. [pic]

15th $167...