Answer:
The sample required is 
Step-by-step explanation:
From the question we are told that
The standard deviation is 
The margin of error is 
Given that the confidence level is 99% then the level of significance is mathematically evaluated as



Next we will obtain the critical value
from the normal distribution table(reference math dot armstrong dot edu) , the value is

The sample size is mathematically represented as
![n = [ \frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%20%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%7D%20%2A%20%20%5Csigma%20%7D%7BE%7D%20%5D%5E2)
substituting values
![n = [ \frac{ 2.58 * 9 }{2} ]^2](https://tex.z-dn.net/?f=n%20%3D%20%5B%20%5Cfrac%7B%202.58%20%2A%20%209%20%7D%7B2%7D%20%5D%5E2)

8 ( 4 - x ) = 7x + 2
32 - 8x = 7x + 2
-7x -7x
--------------------------
32 - 15x = 2
-32 -32
----------------------------
-15x = -30
/-15 /-15
x = 2.
Answer:
4:5
Step-by-step explanation:
half of 16 is 8, and half of 8 is 4
and half of 20 is 10, and half of 10 is 5
hope i helped man
Answer:
10 books per box
Step-by-step explanation:
40÷4
=10
10×4= 40