I was hoping to get some help with these last few questions on my statistics class homework. I would really appreciate it as it is due soon. Thanks!

Exercise 1:

Suppose we wish to assess whether more than 60% of all U.S. households in a particular income class bought life insurance last year. An insurance survey is based on 100 randomly selected U.S. households in the income class and 64 bought life insurance last year. Assuming p = 0.60,

1) What the mean for the sampling distribution of proportions?

2) What is the standard deviation for the sampling distribution of proportions?

3) What is the probability of observing a sample proportion that is at least 0.64?

Exercise 2:

A randomly selected sample of marketing professionals was presented with various scenarios involving ethical issues. One issue was the use of ultraviolet ink on a mail survey promising confidentiality. The ink was used to identify the respondents for adequate cross-tabulation of the data. Of the 205 marketing researchers surveyed, 117 said they disapproved of the action.

1) Compute the 95% confidence interval for population proportion of disapproval the action?

2) Compute the 99% confidence interval for population proportion of approval the action.

Exercise 3:

Cholesterol Case: According to recent studies, cholesterol levels in healthy U.S. adults average about 215 mg/dL with a standard deviation of about 30 mg/dL and are roughly symmetric and unimodal. Consider the cholesterol levels of a random sample of 36 healthy U.S. adults.

1. What is the shape of the sampling distribution?

1. What is the mean of the sampling distribution?

1. What is the standard deviation of the sampling distribution?

1. What is the probability that the average cholesterol level will be greater than 220?

Exercise 4:

A clinic offers a weight-reduction program and is studying the "end of program" weight loss. A random sample of 40 patients' records found a mean weight loss of 16.4 pounds with a standard deviation of 5.4 pounds.

1. If you want to find a confidence interval for the mean weight loss, is it necessary to know that the population distribution of weight loss is normally distributed? Explain why or why not.

1. What is your margin of error for a 95% confidence interval for the mean weight loss?

1. By hand, find a 95% confidence interval for the mean weight loss of all the patients in the program.

1. Explain the meaning of the confidence interval.

1. Can you be 95% confident the mean weight loss for the program is greater than 15 pounds? Explain.