Asurvey 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

0.0775

Step-by-step explanation:

Given : Mean :

Standard deviation :

Sample size :

Since its normal distribution , then the formula to calculate the z-score is given by :-

For x= 28.2 hours

For x= 30 hours

The P- value =

Hence, the probabiliy that the average time spent stydying for the sampe was between 28.2 and 30 hours = 0.0775