A businessman who flies frequently from New York to Philadelphia and also from New York to Boston believes that the in-air flight times are more variable for the Philadelphia flights (despite similar average in-air flight times). He carefully records the in-air flight times (in minutes) for his next ten flights to each location, and finds the following, where y and s represent the mean and standard deviation in the flight times to each location: Destination n ȳ s
Philadelphia 10 34.5 4.5
Bostan 10 39.0 3.0

Required:
a. Can the businessman conclude at the 0.05 significance level that the standard deviation in flight times is greater for flights to Philadelphia?
b. What assumptions are needed in order for the the test in part (a) to be reasonable?