# Confidence intervals

A Variable has a mean of 100 and a standard deviation of 16. Four observations of this variable have a mean of 108 and a sample standard deviation of 12. Test whether the sample has been drawn from the population.

a. Standardized version of x (sample mean).

b. Studentized version of x (sample mean).

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#### Solution Preview

Population mean M = 100

Standard deviation s= 16

Sample mean x= 108

Standard deviation s= 12

Sample size= 4

Significance level is not mentioned. Let us assume it to be alpha (a) = 0.05

We have to test whether the sample is from the population.

a. Standardized ...

#### Solution Summary

The solution calculates Confidence intervals for the population mean and tests whether the sample has been drawn from the population.

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