Answer: 
Step-by-step explanation:
Given: A mirror with a parabolic cross section is used to collect sunlight on a pipe located at the focus of the mirror.
The pipe is located 8 inches from the vertex of the mirror.
Assume the vertex is at the origin.
If the parabola opens upwards
then the coordinates of focus= (0,8)
We know that equation of parabola with focus (0,a) and open upards is of the form (vertex=(0,0)) is

Substitute the value of a=8 in equation, we get


Therefore, equation of the parabola that models the cross section of the mirror is 
First, you divide 58 bars by 4. The answer will be 14 boxes with 2 bars remaining in the box.
Answer:


a. What is the probability that the cost will be more than $450?
We are supposed to find P(x > 450)
Formula : 


Refer the z table :
P(z<0.9431)=0.8264
P(z> 0.9431)=1-P(z<0.9431)=1- 0.8264= 0.1736
Hence the probability that the cost will be more than $450 is 0.1736
b)What is the probability that the cost will be less than $250?
We are supposed to find P(x<250)
Formula : 


Refer the z table :
P(z<-1.3295)=0.0934
Hence the probability that the cost will be less than $250 is 0.0934
c)What is the probability that the cost will be between $250 and $450?
P(250<z<450)=P(z<450)-P(z<250) = 0.8264 - 0.0934 =0.733
Hence the probability that the cost will be between $250 and $450 is 0.733
d) If the cost for your car repair is in the lower 5% of automobile repair charges, what is your cost?
p = 0.05
refer the z table
z = -1.65
Formula : 




Hence If the cost for your car repair is in the lower 5% of automobile repair charges, so, cost is $221.8