An airline is interested in whether the 7 a.m. flight from Sydney to Melbourneis commercially viable. To study the problem they collect data on the number ofpassengers per flight for a random sample of 60 flights. Some Excel output from the sample is shown below:

mean: 135.63
standard error: Null
median:138.5
mode:150
standard deviation:23.78
sample variance:565.69
kurtosis: -0.89
skewness: -0.19
range:89
minimum: 91
maximum: 180
sum:8138
count: 60

(a) Construct a 95% confidence interval for the average number of passengers per flight. you should justify any assumptions that need to be made in order for the confidence interval to be reliable.

(b) The airline has decided to continue to operate this flight only if there is an average of more than 130 passengers per flights. would you advise the company to continue to operate the flight? Explain why or why not? Your answer should be in the form of a hypothesis test and you should justify any assumptions that need to be made in order for your conclusions to be reliable.