Question

The average cholesterol level in the general US population is 189 mg/dL. A researcher wants to...

The average cholesterol level in the general US population is 189 mg/dL. A researcher wants to see if the average cholesterol for men in the US is different from 189 mg/dL. She takes a sample of 81 American males and finds a sample mean of 194 mg/dL and a sample standard deviation of 10.4

What is the 90% confidence interval? What is the correct interpretation of the confidence interval from question 11? Are the assumptions met? Explain.

Conduct a hypothesis test at the 0.10 significance level to test the researcher’s question.

What are the hypotheses? What is the significance level? What is the value of the test statistic? What is the p-value?

What is the correct decision? A. Reject the Null Hypothesis B. Fail to Reject the Null Hypothesis C. Accept the Null Hypothesis D. Accept the Alternative Hypothesis

What is the appropriate conclusion/interpretation? Are the assumptions met? Explain

Homework Answers

Answer #1

The 90% confidence interval is between 192.08 and 195.92.

We are 90% confident that the true average cholesterol for men in the US is between 192.08 and 195.92.

The one-sample t-test has four main assumptions:

  • • The dependent variable must be continuous (interval/ratio).
  • • The observations are independent of one another.
  • • The dependent variable should be approximately normally distributed.
  • • The dependent variable should not contain any outliers.

The assumptions are met.

The hypothesis being tested is:

H0: µ = 189

Ha: µ ≠ 189

The significance level is 0.10.

The value of the test statistic is 4.327.

The p-value is 0.0000.

A. Reject the Null Hypothesis

Therefore, we can conclude that the average cholesterol for men in the US is different from 189 mg/dL.

The assumptions are met.

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