SOLUTION: Hello, I am having a very difficult time figuring this statistics problem. I appreciate any help. A study of 47 golfers show that their average score on a particular course was

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Question 308673: Hello, I am having a very difficult time figuring this statistics problem. I appreciate any help.
A study of 47 golfers show that their average score on a particular course was 97. The standard deviation of the sample is 7. Find the 99% confidence interval of the mean score for all golfers.

Found 2 solutions by rapaljer, Fombitz:
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
The 99% confidence level means that you include 3 standard deviations from the mean. In this case, the standard deviation is 7, and 3*7=21. Now, from the mean of 97, both ADD and SUBTRACT 21:

97-21=76
97+21=118

The interval is from 76 to 118. In other words, 99% of the golfers scored between 76 and 118 on this golf course.

Dr. Robert J. Rapalje, Retired

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
You know the mean, the standard deviation, the confidence interval, and the number of golfers.
Plug the data into the formula.
(Xave+%2B-+Z%2Asigma%2Fsqrt%28N%29)
At 99%, Z=2.58
Xave=97
N=47
sigma=7