Answer: 
Step-by-step explanation:
The midline of the function is

This means that to obtain a maximum of 10, when
reaches it's maximum, 1, 
Set up an algebraic equation: b=cost of ball
1.10=1+b+b
1.10=1+2b
subtract 1 from both sides
.10=2b
divide by 2 on both sides
ball=5 cents
Answer:
The Answer is: B. 79% and 89%
Step-by-step explanation:
Subtract 11% from 89 and 100 to get the range:
89 - (89*.11) =
89 - 9.79 = 79.21
100 - (100*.11) =
100 - 11 = 89
Gallons of water drank in 4 days = 120
Gallons of water drank in a day = 120/4
= 30
Gallons of water drank in 28 days = 30 × 28
= 840