Answer:
A sample of 499 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is given by:

In this question, we have that:

90% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 90% confidence level with an error of at most 0.03
We need a sample of n, which is found when
. So






Rounding up
A sample of 499 is needed.
X=14
2x=28
4x-9=47
you solve for x after you add all the sides
Answer:
The answer is 2/5 or 5.25
Step-by-step explanation:
5 sections so out of 5 and it said A or B so it is 2/5
Answer:
They sold 67.50 in total
Step-by-step explanation:
If each of them sold 15 boxes for 2.25 then both of them got 33.75 each then you add it and that gives you 67.50