A country's education department reported that in2015 ,66.5 % of students enrolled in college or a trade school within 12 months of graduating high school. In 2017 a random sample of 172 individuals who graduated from high school 12 months prior was selected. From this sample,111 students were found to be enrolled in college or a trade school. Complete parts a through c. a. Construct a 95% confidence interval to estimate the actual proportion of students enrolled in college or a trade school within months of graduating from high school in . The confidence interval has a lower limit of and an upper limit of

b. margin of error?

c.Based on this sample, is there any evidence that this proportion has changed since

2015?