2014S Assignment 1 Ans

QMDS 200 Statistics and Data Analysis
Suggested Solutions to Assignment 1

1. Textbook, Problem 1.7 (p.35).
a. numerical, continuous
b. categorical
c. categorical
d. numerical, discrete

2. Textbook, Problem 1.27 (p.39).
a. Categorical variables: (1) gender, (3) current registered class designation, (4) major, (5) intention for graduate school, (7) current employment status, (10) food and dining services satisfaction & (12) type of computer.
b. Numerical variables: (2) age, (6) cumulative grade point average, (8) expected starting annual salary, (9) number of social networking sites, (11) amount of money spending for textbooks and supplies, (13) number of text messages & (14) wealth amount.
c. Discrete numerical variables: (9) number of social networking sites & (13) number of text messages.

3. Textbook, Problem 2.23 (p.65).
a. Cumulative percentage distribution:
Class Boundary (Amount of Soft Drink)
Frequency
Cumulative Percentage
1.965 but less than 1.979
6
20.00%
1.979 but less than 1.993
4
33.33%
1.993 but less than 2.007
6
53.33%
2.007 but less than 2.021
9
83.33%
2.021 but less than 2.035
5
100.00%
Total
30

b. The values are spread almost uniformly over the entire range as shown by similar frequencies in each class in the table above.

Textbook, Problem 2.45 (p.80).
a. Histogram and percentage polygon

b. Cumulative percentage polygon

c. The values are spread almost uniformly over the entire range as shown by similar frequencies in each class in the graphs above.

4. Textbook, Problem 3.59 (p.157).
a.

b. The mean force required to break the insulators in the sample is 1723.4 pounds. The middle ranked breaking force is 1735 pounds. The differences between the smallest and largest breaking force is 348 pounds. The average difference between each value and the mean is 89.55 pounds.
c. The distribution is skewed to the left because the mean is less than the median.
d. All the observations in the sample have breaking force that