2.64 On-time performance of airlines In 2015, data collected on the monthly on-time arrival rate of major domestic and regional airlines operating between Australian airports is numerically summarized by xQ = 85.93, Q1 = 83.75, median = 85.65, Q3 = 87.75, number of observations = 72.

a. Interpret the quartiles.

b. Would you guess that the distribution is skewed or roughly symmetric? Why?