Question 8.
The best answer would be A, two times y divided by 7.
Question 9.
The distributive property. Or A.
Question 10.
5(2+y) would be the answer. So, D.
Hope this helps!
Answer:
The standard deviation of the sample mean differences is _5.23_
Step-by-step explanation:
We have a sample of a population A and a sample of a population B.
For the sample of population A, the standard deviation
is

The sample size
is:
.
For the sample of population B, the standard deviation
is

The sample size
is:
.
Then the standard deviation for the difference of means has the following form:

Finally

Answer:
4600
Step-by-step explanation:
We can write a proportion to find the total amount who attend university using the information given. A proportion is two equivalent ratios set equal to each other. Since 70% live on campus, then 30% live off campus and we are told that number is 1,380.

We will cross multiply the numerator of one ratio with denominator of the other. And then solve for y.
30y=100(1380)
30y=138000
y=4600.
There are 4600 students who attend the university.