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mexicnfmle
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Homework Statement
The Warren County Telephone Company claims in its annual report that “the typical customer spends $60 per month on local and long distance service.” A sample of 12 subscribers revealed the following amounts spent last month.
$64 $66 $64 $66 $59 $62 $67 $61 $64 $58 $54 $66
a. What is the point estimate of the population mean?
b. Develop a 90 percent confidence interval for the population mean.
c. Is the company’s claim that the “typical customer” spends $60 per month reasonable?
Justify your answer using the confidence interval.
Homework Equations
Sample population? 12
Mean=$63
Confidence Interval 90%
The Attempt at a Solution
I know I can use megastats to solve this problem, I am just drawing a blank on which formula to use. WHen I click on Descriptive statistics, it comes back saying "not enough data selected". I tried Confidence Interval and I tried both:
Sample size-mean
sample size- p
I must be entering something wrong somewhere.
Can someone just tell me which formula to use? I am drawing a blank..
Thanks,
Emily