1. What figures should be written in the left-hand column of Table 12.1, in the text, to produce a similar table based on a confidence level of 99 percent? For a confidence level of 99 percent, the margin of error is approximately equal to 1.29/n.

2. Given the following group of people together with their weights, what is the average weight in the sense of mean, median, and mode?

Number of people Weight

2................................................150

4................................................160

3................................................170

1................................................180

1................................................190

1................................................200

1................................................220

2................................................230

3. Given the following group of people together with their salaries, what is the average salary in the sense of mean, median, and mode?

Number of people Salary

1..........................................$95,000

2............................................85,000

1............................................70,000

3............................................40,000

1............................................30,000

2............................................20,000

5............................................15,000

4. A day-care center cares for ten children. Their ages are 1, 1, 2, 2, 2, 3, 3, 4, 6, 6. Construct a histogram that represents the distribution of ages. What is the mean age? What is the variance and standard deviation of these ages?

5. A small company has five employees who missed work during a certain month. The number of days missed were 1, 1, 2, 4, 7. What is the mean number of days missed? What is the variance and standard deviation of this set of data?

6. An instructor gave a ten-question multiple-choice quiz to twelve students. The scores were 10, 10, 9, 9, 8, 8, 8, 7, 7, 7, 7, 6. What is the mean score? What is the variance and standard deviation of these scores?

Compute the answers to the following questions: