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

Usinf these data, construct a 90% confidence interval for the average net change in a students scores aftee completing the course. assume the population is approximately normal.

Step 2 of 4: calculate the sample standard deviation for the given sample data. round your answer to one decimal place.