Question

If X=119​, σ=29​, and n=33​, construct a 95​% confidence interval estimate of the population​ mean,

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Answer 1

n,number of observations=33

Standard deviation=29

Sample Mean=119

For 95% confidence interval the value of z-statistic is=1.96

Now we know the CI is calculated using the formulae:

_{=119-1.96(29/(33)^0.5)<=u<=119+1.96(29/(33)^0.5)}

_{=119.1-9.89<=u<=119.1+9.89}

_{=109.11<=u<=128.99 is the confidence interval of the population mean.}