Answer:
80.0456<[tex]\bar x[/tex]<81.1210
Step-by-step explanation:
-Given the mean, [tex]\bar y=80.5833[/tex] and [tex]s=2.77369[/tex], the confidence interval can be calculated using the formula:
[tex]\bar x\pm z\times \frac{\sigma}{\sqrt{n}}[/tex]
#We substitute our values in the formula to solve for CI:
[tex]=\bar x\pm z\times \frac{\sigma}{\sqrt{n}}\\\\=\bar y\pm z_{0.05}\times \frac{s}{\sqrt{72}}\\\\=80.5833\pm 1.645\times \frac{2.77369}{\sqrt{72}}\\\\=80.5833\pm0.5377\\\\=[80.0456,81.1210][/tex]
Hence, the confidence interval lies between 80.0456 and 81.1210