Answer:
Are there answer choices?
Step-by-step explanation:
Answer:
a = 29
u = 12
Step-by-step explanation:
32 + 7u + 9 + 2a - 3 = 3a + 7u + 9
32 + 2a - 3 = 3a
a = 29
3(29) + 7u + 9 = 180
7u = 180 - 96
7u = 84
u = 12
Answer:
The required sample size for the new study is 801.
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:

25% of all adults had used the Internet for such a purpose
This means that 
95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What is the required sample size for the new study?
This is n for which M = 0.03. So






Rounding up:
The required sample size for the new study is 801.