Answer-
The 90% confidence interval of the sample is (140.04,160.5).
Solution-
Assuming it as normal distribution,
Number of observations n = 35
Mean = X = 150.27
Standard Deviation = s = 30.87
Then Confidence Interval we want: 95%, Then the Z value for that Confidence Interval is Z = 1.960
Using that Z in this formula for the Confidence Interval,
[tex]\overline{X}\ \pm \ Z\frac{S}{\sqrt{n} }[/tex]
Putting all the values,
[tex]150.27 \pm \ 1.96\frac{30.87}{\sqrt{35}} = 150.27 \pm 10.23 = (140.04,160.5)[/tex]
