What? Sorry can’t understand
<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.
Answer:
Step-by-step explanation:
22. √125 is closer to √121 or 11
23. √23.5 is closer to √25 or 5
24. ∛59 is closer to ∛64 or 4 (cubed)
(4 cubed = 64, 3 cubed = 27)
25. ∛430 is closer to ∛512 or 8
(512 - 430 = 82
430- 343= 87)
26. y² = 55 is equal to y = √55, Closer to √49 or 7
27. d² = 95 is equal to d = √95, Closer to √100 or 10
28. p² = 6.8 is equal to p = √6.8, Closer to √9 or 3
29. ∛210 is closer to ∛216 or 6 (cubed)
30. ∛520 is closer to ∛512 or 8 (cubed)
Then 70% of volcanos wouldn't be in California.