Answer:
The 90% confidence interval for the mean score of all takers of this test is between 59.92 and 64.08. The lower end is 59.92, and the upper end is 64.08.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 62 - 2.08 = 59.92
The upper end of the interval is the sample mean added to M. So it is 62 + 2.08 = 64.08.
The 90% confidence interval for the mean score of all takers of this test is between 59.92 and 64.08. The lower end is 59.92, and the upper end is 64.08.
Answer:
Step-by-step explanation:
x₁ = 0 ; y₁=0 &
x₂ = 1 ; y₂=2
Slope =

Slope = 2
H=-5(t^2 - 16t)
H=-5(t^2 - 16t +64)+320
H=-5(t-8)^2 +320
Vertex is at (8, 320)
The max height is 320 m.
No she's not correct,,,
If the teas are $50 to start with 20% up from $50 is $62.50
if she counts down 20% down from that it wouldn't be $50 but be $40.
So she would not break even.