Question

# 1) Do students change their study habits in classes where they achieve a higher midterm score?...

1) Do students change their study habits in classes where they achieve a higher midterm score? A researcher wants to explore this question for a particular macroeconomics class. She recruits 8 students who performed well on the midterm exam and compares their before and after weekly hours studying as below:

 Students 1 2 3 4 5 6 7 8 Before 15 14 17 17 19 14 13 16 After 9 9 11 10 19 10 14 10

Assuming differences in study time are generally normally distributed, use a 1% significance level to determine if study times after the midterm have changed in high performing students (use critical values).

(a) Null and Alternative Hypotheses

 t-Test: Paired Two Sample for Means Before After Mean 15.625 11.5 Variance 3.982142857 11.71428571 Observations 8 8 Pearson Correlation 0.491533925 Hypothesized Mean Difference 0 df 7 t Stat 3.892951269 P(T<=t) one-tail 0.00297635 t Critical one-tail 2.997951567 P(T<=t) two-tail 0.005952699 t Critical two-tail 3.499483297

TS = 3.892951269 > critical value (3.499483297)

hence we reject the null hypothesis