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
Answer:
It will take Ellie 64 minutes to put as many boxes as possible.
Step-by-step explanation:
Let us work with meters.
The dimensions of Ellie's boxes in meters are: 0.45m by 0.40m by 0.35 ( <em>to convert from centimeters to meters we just divide by 100, because 1m =100cm).</em> therefore the volume of each box is:
<em>
</em>
Now the dimensions of the empty van are 3.6m by 1.6m by 2.1 m, therefore its volume 
is:
So the amount of boxes that Ellie can put in the van is equal to the volume of the van divided by the volume 
of each box:
So 192 boxes can be put into the van.
Now Ellie can put 3 boxes in the van in 1 minute, therefore the amount of time it will take her to put 192 boxes into the van will be:
So it takes Ellie 64 minutes to put as many boxes into the van as she can.
Answer:
The correct answers are "After adding the 0 test score, the mean would be affected.", ad "Before the missed test, Eva’s median score was 91".
Step-by-step explanation:
We know that the mean and median scores would not be helpful in determining Eva's abilities since the 0 is not a representation of how much she knows. However, it will affect the average as adding a 0 to the numerator and a 1 to the denominator will lower the average.
Finally, we can tell the median is 91 before added as when we line up the scores in ascending order, the middle number is 91.
82, 90, 91, 96, 100
