Answer: Tt is unlikely to have change in the sample mean score is less than 10 points .
Step-by-step explanation:
Given : Mean :
Standard deviation :
Sample size : n= 100
We assume that the change in students scores are normally distributed.
Let X be the random variable that represents the change in students scores .
Z score :
For x = 10
By using the standard normal distribution table , the probability that the change in the sample mean score is less than 10 points :-
Since the calculated probability is less than 0.5.
So , we say that it is unlikely to have change in the sample mean score is less than 10 points .