Answer Happy

A certain test preparation course is designed to help students improve their scores on the GMAT 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 4 students scores on the exam after completing the course: 11. 13,9.8 Using these data. construct a 90 Se confidence interval for the average net change in a student's 5 core after completing the course. Assume the population is approximately normal. Step 1 of 4: Calculate the sample mean for the given sample data. Round your answer to one decimal place. Step 2 of 4 : Calculate the sample standard devation for the given sample data. Round your answer to one decimal place. Step 3 of 4 : Find the critical yalue that should be used in constructing the confidence interval. Round your answer to three decimal places. Step 4 of 4 : Construct the 90% confidence interval. Round your answer to one decimal place: