<h2>Answer with explanation:</h2>
Let be the population mean.
By observing the given information, we have :-
Since the alternative hypotheses is left tailed so the test is a right-tailed test.
We assume that the time spend by students per day is normally distributed.
Given : Sample size : n=121 , since n>30 so we use z-test.
Sample mean :
Standard deviation :
Test statistic for population mean :-
Critical value (one-tailed) corresponds to the given significance level :-
Since the observed value of z (-7.79) is less than the critical value (1.2816) , so we do not reject the null hypothesis.
Hence, we conclude that we have enough evidence to accept that the college students spend an average of 4 hours or less studying per day.