Question

What are the chances your flight will leave on time? Below are a histogram and summary statistics for the percentage of flights departing on time each month from thru 2006. There is no evidence of a trend overtime. Find a 90% confidence interval for the true percentage of flights that depart on time

Answer 1

Answer:

80.0456<$\bar x$<81.1210

Step-by-step explanation:

-Given the mean, $\bar y=80.5833$ and $s=2.77369$, the confidence interval can be calculated using the formula:

$\bar x\pm z\times \frac{\sigma}{\sqrt{n}}$

#We substitute our values in the formula to solve for CI:

$=\bar x\pm z\times \frac{\sigma}{\sqrt{n}}\\\\=\bar y\pm z_{0.05}\times \frac{s}{\sqrt{72}}\\\\=80.5833\pm 1.645\times \frac{2.77369}{\sqrt{72}}\\\\=80.5833\pm0.5377\\\\=[80.0456,81.1210]$

Hence, the confidence interval lies between 80.0456 and 81.1210