A survey among freshman at a certain university revealed that the number of hours spent studying before final exams was normally
distributed with mean 25 and standard deviation 15. A sample of 36 students was selected. What is the probabiliy that the average time spent stydying for the sampe was between 28.2 and 30 hours
0.15 cents is 10 percent of 1.50, and that multiplied by 2 is 0.30 cents. 0.30 cents is equal to 20 percent, and the difference between 1.50 and 1.20 is 30 cents.