I really need help answering these problems please. I am having a very hard time getting through this chapter. Thank you in advance!

Question 1

In a sample of seven cars, each car was tested for nitrogen-oxide emissions(in grams per mile) and the following results were obtained: 0.12, 0.18, 0.17, 0.16, 0.06, 0.19, 0.07. Assuming that this sample is representative of the cars in use, construct a 98% confidence interval estimate of the mean amount of nitrogen-oxide emissions for all cars. If the EPA requires that nitrogen-oxide emissions be less than 0.165 g/mi, can we safely conclude that this requirement is being met?

What is the confidence interval estimate of the mean amount of nitrogen-oxide emissions for all cars?

___g/mi

Round to three decimal places as needed.

Question 2

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the sample data to construct a 95% confidence interval estimate of the mean duration of game play. 4051 3880 3860 4033 4323 4816 4661 4036 5003 4828 4336 4325

a) What is the confidence interval estimate of the population mean ?

b) Use the sample data to construct a 99% confidence interval estimate of ?, the standard deviation of the duration times of game play.

Question 3

In a study designed to test the effectiveness of magnets for treating back pain, 40 patients were given a treatment with magnets and also a sham treatment without magnets. Pain was measured using a scale from 0 (no pain) to 100 (extreme pain). After given the magnet treatments, the 40 patients had pain scores with a mean of 12.2 and a standard deviation of 2.2. After being given the sham treatments, the 40 patients had pain scores with a mean of 10.5 and a standard deviation of 2.5.

a. Construct the 90% confidence interval estimate of the mean pain score for patients given the magnet treatment. What is the confidence interval estimate of the population mean ?

b. Construct the 90% confidence interval estimate of the mean pain score for patients given the sham treatment. First calculate E, rounding to three decimal places.

c.Compare the results. Does the treatment with magnets appear to be effective?

Question 4

A physician wants to develop criteria for determining whether a patient's pulse rate is atypical, and she wants to determine whether there are significant differences between males and females. Use the sample pusle rates below.

Male96 76 56 64 76 56 60 68 68 76

Female72 76 104 64 72 72 60 72 88 124

a) Construct a 95% confidence interval estimate of the mean pulse rate for males.

b) Construct a 95% confidence interval estimate of the mean pulse rate for females.

c) Compare the preceding results. Can we conclude that the population means for males and females are different? Why or why not?