A department store chain has ten stores in a state. After a review of sales records, it was found that compared with the same period last year, the following percentage increases in dollar sales had been achieved over the Christmas period this year: 10.2 3.1 5.9 7.0 3.7 2.9 6.8 7.3 8.2 4.3 For this population:

(a) Find the mean percentage increase in dollar sales.

(b) Find the median.