Answer:
Step-by-step explanation:
n - 66 = -35
n = 31
Answer:
A=1.75
Step-by-step explanation:

I think it would cost $120 dollars I'm not quite sure...
Answer:
A sample size of 128 is needed.
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(square root of the variance) and n is the size of the sample.
How large should a sample be if the margin of error is 1 minute for a 93% confidence interval
We need a sample size of n, which is found when
. We have that
. So





Rounding up
A sample size of 128 is needed.