I believe the answer is 4.
Answer: 95.45 %
Step-by-step explanation:
Given : The distribution is bell shaped , then the distribution must be normal distribution.
Mean : 
Standard deviation :
The formula to calculate the z-score :-

For x = 13

For x = 19

The p-value = 

In percent, 
Hence, the percentage of data lie between 13 and 19 = 95.45 %
Answer:
40 1/4
Step-by-step explanation:
160 is a multiple of 4
160 / 4 = 40
40 1/4
A function is positive if it lies above the x axis.
This function is positive before x = -4, i.e. over the interval 
It is negative elsewhere, i.e. over the interval 
So, the only correct option is the second one.
Nothing can go into 83 so of you square root it you will get a decimal so the nearest whole number You would get is 9 because 9*9=81 and that's the closet that you will get to 83