Practice Questions for Chapter 10
Here are some sample test questions for Chapter 10.
If the margin of error in an estimate for the mean weight of a shipment is + or - 2 pounds at a confidence level of 95 percent, what will be the margin of error at a confidence level of 98 percent?
Suppose that in a survey we find that 37 percent of people prefer Shaul's chicken to Shalom's. How large a sample would you need to know that the margin of error for a 95 percent confidence interval is no more than 3 percent? If the confidence level were 90 percent, would the minimum sample size be larger or smaller?(Hint--you can calculate the standard deviation because it is a binomial model.)
A school claims that 80 percent of its students get into one of their top three choices for college. The statistics teacher decides to test this at a 5 percent level of significance. Comment on the validity of each of the following interpretations of the 5 percent significance level:
The null hypothesis is that the average high temperature in December is 45 degrees. If someone reports that the average was 52 degrees and that the P-value for this is .036, what does the P-value represent?