A random sample of 16 students showed an average age of 25 years and a standard deviation of 2 years. The 98% confidence interval for the true average age of students is what?

1 Answer
BeeFree
Jan 26, 2016

The standard error of the sampling distribution of means is:

s.e. #=2/sqrt16=1/2# years old

Explanation:

Next, use the Standard Normal table to find the lower and upper limits for a total area under the curve equal to #98%#:

#z=+-2.326# standard deviations

Lastly, the confidence interval will be centered at the mean #barx=25# years old ...

C.I. #=25+-(2.326)(1/2)=[23.837, 26.163]#

hope that helped

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