Stats Study Sheet

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1.Assume 20% of all email is spam. A large Internet provider plans on conducting a survey of 900 emails to see what percentage are spam. a.What is the probability they will get a proportion greater than 0.1836?

b.If they get a sample proportion over 24% they are going to shut down their email server. What is the probability this will happen?

2.A survey is done to estimate the proportion of U.S. adults who think that cell phone use while driving should be illegal. In the survey, 54% of a randomly selected sample of 1025 individuals said that cell phone use while driving should be illegal. a.What is the 90% confidence interval for the proportion of adults who think cell phone use should be illegal?

1. A sample of college students was asked whether they would return the money if they found a wallet on the street. Of the 93 women, 84 said “yes,” and of the 75 men, 53 said “yes.” Assume that these students represent all college students (Data source is from UC Davis and can be found in the textbook). a. Is there enough data to calculate a confidence interval for the women?

2. A sample of college students was asked whether they would return the money if they found a wallet on the street. Of the 93 women, 84 said “yes,” and of the 75 men, 53 said “yes.” Assume that these students represent all college students (Data source is from UC Davis and can be found in the textbook). b. Is there enough data to calculate a confidence interval for the women?

3.A CNN/Time poll conducted in the United States October 23-24, 2002, (http://www.pollingreport.com) asked, “Do you favor or oppose the legalization of marijuana?” In the nationwide poll of n = 1007 adults, 34% said that they favored legalization. a.Find the margin of error for a 96% confidence interval.

3. A medical researcher wants to study whether oral contraceptives are correlated with high blood pressure. A sample of 500 women using oral contraceptives showed...
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