The University’s job placement center randomly samples former graduates to see how many of them have found employment in the field of their degree. The center wishes to determine if job placement has changed over the last 10 years. A sample of 200 graduates from 10 years ago was randomly selected and surveyed and another sample of 400 graduates from 2 years ago was randomly selected and surveyed. Of the graduates surveyed, 90% of the graduates from 10 years ago and 87.5% of the graduates from 2 years ago had found employment in the field of their degree.
a) Construct the 95% confidence interval.
b) What is the margin of error?
c) Interpret your interval in the context of this problem.
d) Based on the confidence interval from part (a), does it appear that job placement has changed over the last 10 years? Support your answer.