1 / 7

Chapter 7 Review

Chapter 7 Review. WARM UP. Assume the duration of human pregnancies can be described by a Normal model with mean 266 days and standard deviation 16 days a. What percentage of pregnancies should last between 270 and 280 days? 

austinb
Download Presentation

Chapter 7 Review

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. Chapter 7 Review

  2. WARM UP • Assume the duration of human pregnancies can be described by a Normal model with mean 266 days and standard deviation 16 days • a. What percentage of pregnancies should last between 270 and 280 days?  • b. At least how many days should the longest 25% of all pregnancies last? • c. Suppose a certain obstetrician is currently providing care to 60 pregnant women. What’s the probability that the mean duration of these patients’ pregnancies will be less than 260 days?

  3. Practice • The article “Thrillers” (Newsweek,Apr. 22, 1985) states, “Surveys tell us that more than half of America’s college graduates are avid readers of mystery novels.” Assume the true proportion is exactly 0.5. What is the probability that an SRS of 225 college graduates would give a sample proportion greater than 0.6?

  4. Practice • Suppose that a particular candidate for public office is in fact favored by 48% of all registered voters in a sizable metropolitan district. A polling organization takes an SRS of 500 voters and will use the sample proportion to estimate the population parameter. What is the probability that the sample proportion will be greater than 0.5, causing the polling organization to incorrectly predict the results of the upcoming election?

  5. Practice • The Gallup Poll once asked an SRS of 1540 adults,“Do you happen to jog?” Suppose 15% of all adults jog. Find the probability the poll gave a result within 2% of the actual population proportion.

  6. Practice • A soft drink bottler claims that, on average, cans contain 12 oz. of soda. Suppose the true distribution of soda volumes is normally distributed with a mean of 12 oz. and a standard deviation of .16 oz. Sixteen cans are randomly selected and their volumes are measured. What is the probability the average volume will be between 11.96 and 12.08 oz.?

  7. Practice • The distribution of scores for persons over 26 years of age on the Wechsler Adult Intelligence Scale (WAIS) is approximately normal with a mean of 100 and a standard deviation of 15. • A. What are the mean and standard deviation of the average WAIS score for a SRS of 60 people? • B. What is the probability that the average WAIS score of a SRS of 60 people is 105 or higher? • C. Would your answers to parts A and B be affected if the population was skewed left rather than Normal?

More Related