1 / 7

8.4 z Test for a proportion

8.4 z Test for a proportion. Since a normal distribution can be used to approximate the binomial distribution when np  5 and nq  5, the standard normal distribution can be used to test hypotheses for proportions. The formula for the z test for a proportion is where. Formula.

shaine-graham
Download Presentation

8.4 z Test for a proportion

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. 8.4 z Test for a proportion

  2. Since a normal distribution can be used to approximate the binomial distribution when np 5 andnq5, the standard normal distribution can be used to test hypotheses for proportions. The formula for the z test for a proportion is where Formula

  3. A dietician claims that 60% of people are trying to avoid trans fats in their diets. She randomly selected 200 people and found that 128 people stated that they were trying to avoid trans fats in their diets. At α = 0.05, is there enough evidence to reject the dietitian’s claim? Step 1: State the hypotheses and identify the claim. H0: p = 0.60 (claim) and H1: p  0.60 Step 2: Find the critical value. Since α= 0.05 and the test is a two-tailed test, the critical value is z = ±1.96.

  4. Step 3: Compute the test value. • Step 4: Reject/Not Reject • Step 5: Sentence There is not enough evidence to reject the claim that 60 of people are trying to avoid trans fats in their diets.

  5. The Family and Medical Leave Act provides job protection and unpaid time off from work for a serious illness or birth of a child. In 2000, 60% of the respondents of a survey stated that it was very easy to get time off for these circumstances. A researcher wishes to see if the percentage who said that it was very easy to get time off has changed. A sample of 100 people who used the leave said that 53% found it easy to use the leave. At α = 0.01, has the percentage changed?

  6. An attorney claims that more than 25% of all lawyers advertise. A sample of 200 lawyers in a certain city showed that 63 had used some form of advertising. At α = 0.05, is there enough evidence to support the attorney’s claim?

More Related