The following table shows the off-seasonal average air ticket prices (2021) of seven popular domestic airlines in Australia from Melbourne to Sydney (per person - one way). Name of the Airline Average ticket price ($) Jetstar 142 Tiger Airways 136 Qantas Domestic 136 Virgin Australia 141 Rex Airline 135 United Airlines 131 Delta 145 a) What is the mean air ticket price for the above sample? b) What is the IQR (Inter Quartile Range) of the above data set? c) The z-score for the Virgin Australia ticket price was found to be 1.37. What is the standard deviation of the data set? d) What is the coefficient of variation?