This is an A. <span>observational study. They are observing the use of cell phones differs between people with or without cancer.
Happy studying ^-^</span>
A. there are 20 boys and 30 girls.
B.
68.7 out of 100 Boys
Girls im not sure, maybe someone else can answer that sorry
Hope I'm right and this helps sorry i didn't get girls.
Answer:
The average rate of change is 8.
Step-by-step explanation:
The formula to calculate the average rate of change of a function F(x) is:

In this case, F(x) = 
a=2 and b=4
You have to evaluate x=2 (which is a in the formula) and x=4 (which is b in the formula) in the function.
In order to obtain F(b) and F(a) you have to replace x=4 and x=2 in the given function:
F(b) = 
F(a) = 

The answer is 8.
Answer:
4x-6
Step-by-step explanation:
Two times 2 equals 4 and 2 times 3 equals 6
Answer:3+(-6)
Step-by-step explanation: