A certain test preparation course is designed to help students improve their scores on the USMLE 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 23,29,23 ing these data, construct a 90% confidence interval for the average not change in a student's score after completing the course Adsume the population is approximately normal Step 3 of 4: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places Copy Data