The answer would be 4 over 5 or 4/5
<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.
Area of square base = 324 m²
Length of the square side = √324 = 18
The side of the square is the base of the triangle.
Area of triangle = (1/2)*base* height
135 = (1/2)*18* h
135 = 9h
135/9 = h
15 = h
height = 15 m
To get the height of the Pyramid, the height of the Triangle and half the length of the side of the square form a right angled triangle.
Hypotenus = 15
Half length of square = 18/2 = 9
Height of Pyramid = H
By Pythagoras' Theorem:
15² = H² + 9²
225 =H² + 81
H² + 81 = 225
H² = 225 - 81
H² = 144 Take square root of both sides
H = √144
H = 12
Height = 12 meters.
Option C.
Irrational
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