To test the effectiveness of a business school preparation course, 8 students took a general business test before and after the course. The results are given below.           Exam Score    Exam Score     Student   Before Course   After Course       1     530       670       2     690       770       3     910       1,000       4     700       710       5     450       550       6     820       870       7     820       770       8     630       610Construct the 95% confidence interval for the mean difference between the exam scores before the course and exam scores after the course.