1 / 6

Mixed Examples of Hypothesis Testing & Confidence Intervals

Mixed Examples of Hypothesis Testing & Confidence Intervals. Example 1.

zudora
Download Presentation

Mixed Examples of Hypothesis Testing & Confidence Intervals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Mixed Examples of Hypothesis Testing & Confidence Intervals

  2. Example 1 An insurance company is reviewing its current policy rates. When originally setting the rates they believed that the average claim amount was $1,800. They are concerned that the true mean is actually higher than this, because they could potentially lose a lot of money. They randomly select 40 claims, and calculate a sample mean of $1,950. Assuming that the standard deviation of claims is $500, and set α = .05,test to see if the insurance company should be concerned.

  3. Example 2 A Gallup poll asked Americans to rate their life on a scale of 0 to 10 (0 being the worst possible life and 10 being the best). The 1,000 people who have a television set reported a mean of 6.07 with a standard deviation of 1.1. Of the 300 people without a television set, the mean score was 4.47 with a standard deviation of 2.8. http://www.gallup.com/poll/105850/Ownership-May-Good-WellBeing.aspx Form a 90% confidence interval for the mean difference.

  4. Example 3 Suppose the Acme Drug Company develops a new drug, designed to prevent colds. The company states that the drug is equally effective for men and women. To test this claim, they chose a simple random sample of 100 women and 200 men from a population of 100,000 volunteers. At the end of the study, 38% of the women caught a cold; and 51% of the men caught a cold. Based on these findings, can we reject the company's claim that the drug is equally effective for men and women? Use a 0.05 level of significance.

  5. Example 4 A hospital wants to get an estimate for infection rates of patients coming out of surgery. They observe a random sample of 120 patients who come out of surgery and find that 15 of them develop an infection while recovering. Construct a 95% confidence interval for the infection rate at this hospital. Explain what this confidence interval means. If the hospital wanted to narrow its confidence interval, what should it do?

  6. Example 5 A sample of 40 sales receipts from a grocery store has a mean of $137 and a standard deviation of $30.2. Use these values to test whether or not the mean sales at the grocery store is less than $150.

More Related