# Question: In the past 60 of all undergraduate students enrolled at

In the past, 60% of all undergraduate students enrolled at State University earned their degrees within four years of matriculation. A random sample of 95 students from the class that matriculated in the fall of 2006 was recently selected to test whether there has been a change in the proportion of students who graduate within four years. Administrators found that 40 of these 95 students graduated in the spring of 2010

a. Given the sample outcome, find a 95% confidence interval for the relevant population proportion. Does this interval estimate suggest that there has been in a change in the proportion of students who graduate within four years? Why or why not?

b. Suppose now that State University administrators want to test the claim made by faculty that the proportion of students who graduate within four years at State University has fallen below the historical value of 60% this year. Use this sample proportion to test their claim. Report a p-value and interpret it.

a. Given the sample outcome, find a 95% confidence interval for the relevant population proportion. Does this interval estimate suggest that there has been in a change in the proportion of students who graduate within four years? Why or why not?

b. Suppose now that State University administrators want to test the claim made by faculty that the proportion of students who graduate within four years at State University has fallen below the historical value of 60% this year. Use this sample proportion to test their claim. Report a p-value and interpret it.

## Answer to relevant Questions

Suppose a well-known baseball player states that, at this stage of his career, he is a “300 hitter” or better. That is, he claims that he gets a hit in at least 30% of his at-bats. Over the next month of the baseball ...The managing partner of a major consulting firm is trying to assess the effectiveness of expensive computer skills training given to all new entry-level professionals. In an effort to make such an assessment, she administers ...A large buyer of household batteries wants to decide which of two equally priced brands to purchase. To do this, he takes a random sample of 100 batteries of each brand. The lifetimes, measured in hours, of the batteries are ...Senior partners of an accounting firm are concerned about recent complaints by some female managers that they are paid less than their male counterparts. In response to these charges, the partners ask their human resources ...For testing the difference between two proportions is used as the approximate standard error of p̂1 - p̂2, where p̂c is the pooled sample proportion. Explain why this is reasonable when the null-hypothesized value of p1 ...Post your question