Use the Given Degree of Confidence and Sample Data to Construct

Use the given degree of confidence and sample data to construct a confidence interval for the population mean $\mu$ . Assume that the population has a normal distribution. $n = 30 , \bar { x } = 84.6 , \mathrm {~s} = 10.5,90 \%$ confidence

A) $79.32 < \mu < 89.88$
B) $80.68 < \mu < 88.52$
C) $81.34 < \mu < 87.86$
D) $81.36 < \mu < 87.84$