5/12 Question 4 of 6, Step 1 of 4 Correct A certain test preparation course is designed to help students improve their scores on the MCAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 3 students' scores on the exam after completing the course: 1, 6, 5 Using these data, construct a 98 % confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Copy Data Step 1 of 4: Calculate the sample mean for the given sample data. Round your answer to one decimal place