I don’t know if this will help....
Answer:
C. (36337.32, 48968.68)
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 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 42653 - 6315.68 = 36337.32.
The upper end of the interval is the sample mean added to M. So it is 42653 + 6315.68 = 48968.68.
So the correct answer is:
C. (36337.32, 48968.68)
Answer:
Step-by-step explanation:
(a,9).......we dont know " a " (or x) but we do know y...it is 9
so sub in 9 for y and solve for x
y = 2x + 1
9 = 2x + 1
9 - 1 = 2x
8 = 2x
8/2 = x
4 = x <======= ur answer is D
Regular price: $419
Sale price: (1-0.205)($419) = $333.11
The bike will cost $333.11 before tax. You haven't shared the tax rate, but I can at least tell you that the cost of the bike after tax will be
(1.00 + rate as a decimal fraction)*$333.11.
Example: If the tax rate is 7.5%, then the bike will cost (1.00+0.075)*($333.11).