Answer:
The minimum sample size required to ensure that the estimate has an error of at most 0.14 at the 95% level of confidence is n=567.
Step-by-step explanation:
We have to calculate the minimum sample size n needed to have a margin of error below 0.14.
The critical value of z for a 95% confidence interval is z=1.96.
To do that, we use the margin of error formula in function of n:
The minimum sample size to have this margin of error is n = 567.
"Understand the problem" might rightly consist of
• Perform this step first
• Identify what you are being asked to solve or find.
• Identify the important words or numbers in the problem
• Identify any instructions that you are supposed to follow
_____
One of my professors always insisted we start the solution of any problem by writing down what was Given, and what we had to Find, using those headers for the sections of the paper we turned in. Only after those were listed were we allowed to write the Solution. Solution papers that didn't have that format were tossed in the trash, and no credit was given. Harsh, but effective.
Answer:
95% Confidence interval: (39.43, 61.58)
Step-by-step explanation:
We are given the following in the question:
Sample mean, 
= $50.50
Sample size, n = 15
Alpha, α = 0.05
Sample standard deviation = 20
95% Confidence interval:
Putting the values, we get,
95% Confidence interval: (39.43, 61.58)
B is the answer to this question
