1. A statistics practitioner took a random sample of 41 observations from a population whose standard deviation is 30 and computed the sample mean to be 103.

Note:For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits.

A. Estimate the population mean with 95% confidence.

Confidence Interval =

B. Estimate the population mean with 90% confidence.

Confidence Interval =

C. Estimate the population mean with 99% confidence.

Confidence Interval =

2. The number of cars sold annually by used car salespeople is normally distributed with a standard deviation of 15. A random sample of 300 salespeople was taken and the mean number of cars sold annually was found to be 73. Find the 97% confidence interval estimate of the population mean.

Note:For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits.

Confidence Interval =

3.A statistics practitioner took a random sample of 49 observations from a population whose standard deviation is 23 and computed the sample mean to be 96.

Note:For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits.

A. Estimate the population mean with 95% confidence.

Confidence Interval =

B. Estimate the population mean with 95% confidence, changing the population standard deviation to 47;

Confidence Interval =

C. Estimate the population mean with 95% confidence, changing the population standard deviation to 8;

Confidence Interval =

4. Among the most exciting aspects of a university professor's life are the departmental meetings where such critical issues as the color the walls will be painted and who gets a new desk are decided. A sample of 20 professors was asked how many hours per year are devoted to such meetings. The responses are listed below. Assuming that the variable is normally distributed with a population standard deviation of 9 hours and that you can use the Z-Interval test, estimate the mean number of hours spent at departmental meetings by all professors. Use a confidence level of 94%.

Note:For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits.

Confidence Interval =

5. It is known that the amount of time needed to change the oil on a car is normally distributed with a standard deviation of 5 minutes. A random sample of 95 oil changes yielded a sample mean of 28 minutes. Compute the 92% confidence interval estimate for the population mean.

Note:For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits.

Confidence Interval =

Exhibit 5-10 The probability distribution for the number of goals the Lions soccer team makes per game is given below. Number Of Goals Probability 0.05 0.15 AWNHO 0.35 0.30 0.15 Refer to Exhibit 5-10. The expected number of goals per game is: a. 0 b. 1 c. 2, since it has the highest probability d. 2.35 Refer to Exhibit 5-10. What is the probability that in a given game the Lions will score no goals? a. 0.95 b. 0.05 c. 0.75 d. 0.60 Refer to Exhibit 5-10. What is the probability that in a given game the Lions will score at least 1 goal? a. 0.20 b. 0.55 c. 1.0 d. 0.95 Refer to Exhibit 5-10. What is the probability that in a given game the Lions will score less than 3 goals? a. 0.85 b. 0.55 c. 0.45 d. 0.80