<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:
The walk will cost $8164.
Step-by-step explanation:
Given:
Diameter of the circular pond (D) = 24 yd
Width of the gravel path (x) = 2 yd
Cost per yard of the path = $50
Now, radius of the circular pond is half of the diameter and is given as:

Now, area of the pond is given as:

Area of the complete path including the pond area is given as:

Now, area of the gravel path can be obtained by subtracting the pond area from the total outer area. This gives,

Now, using unitary method,
Cost of 1 square yard of path = $50
∴ Cost of 163.28 square yard of path = 50 × 163.28 = $8164
Hence, the walk will cost $8164.
For me cross multiplying works really well.
Answer:
10>-15
Step-by-step explanation:
633,248.
The difference of each 3 is that they have different place values.
The 3 on the right side is int he 1000s (thousands) place, and the 3 on the left is in the 10,000s (ten thousands) place. :)
The one in the 10,000s place is 10 times larger than the one in the 1,000s place!