1. A quality control specialist for a restaurant chain takes a random sample of size 10 to check the amount of soda served in the 16 oz. serving size. The sample mean is 13.50 with a sample standard deviation of 1.54. Assume the underlying population is normally distributed. Find the 95% confidence interval for the true population mean for the amount of soda served. (Round your answers to two decimal places.(___,___)

2. A quality control specialist for a restaurant chain takes a random sample of size 14 to check the amount of soda served in the 16 oz. serving size. The sample mean is 13.50 with a sample standard deviation of 1.57. Assume the underlying population is normally distributed. We wish to construct a 95% confidence interval for the true population mean for the amount of soda served. What is the error bound? (Round your answer to two decimal places.)

3. A magazine published data on the best small firms in a certain year. These were firms that had been publicly traded for at least a year, have a stock price of at least $5 per share, and have reported annual revenue between $5 million and $1 billion. The table below shows the ages of the corporate CEOs for a random sample of these firms.

49	59	50	60	56
59	74	63	53	50
59	60	60	57	46
55	63	57	47	55
57	43	61	62	49
67	67	55	55	49

Use this sample data to construct a 90% confidence interval for the mean age of CEO's for these top small firms. Use the Student's t-distribution. (Round your answers to two decimal places.)(___,___)

4. A survey organization, as part of the United States Census Bureau, conducts a yearly census similar to the one taken every ten years, but with a smaller percentage of participants. One of these surveys estimates with 90% confidence that the mean household income in the U.S. falls between $69,712 and $69,926. Find the point estimate for mean U.S. household income. (Enter your answer as a whole number.)x =

Find the error bound for mean U.S. household income. (Enter your answer as a whole number.)EBM =

5. Of 1,050 randomly selected adults, 360 identified themselves as manual laborers, 280 identified themselves as non-manual wage earners, 250 identified themselves as mid-level managers, and 160 identified themselves as executives. In the survey, 82% of manual laborers preferred trucks, 62% of non-manual wage earners preferred trucks, 54% of mid-level managers preferred trucks, and 26% of executives preferred trucks. We are interested in finding the 95% confidence interval for the percent of executives who prefer trucks. Which distribution should you use for this problem? (Round your answers to two decimal places.)p' ~N (____,_____)

6. A pharmaceutical company makes tranquilizers. It is assumed that the distribution for the length of time they last is approximately normal. Researchers in a hospital used the drug on a random sample of 9 patients. The effective period of the tranquilizer for each patient (in hours) was as follows: 2.5; 2.9; 3.1; 2.3; 2.3; 2.2; 2.8; 2.1; and 2.4.NOTE: If you are using a Student's t-distribution, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)

(i) Round your answer to two decimal places.x = s_x=

_(II) Which distribution should you use for this problem? (Enter your answer in the form z or t_df where df is the degrees of freedom.)