Calculate the average by multiplying each value by the number of times it occurred, adding those products, and dividing by the total number of minutes, which is 60. First, get the products: 0(15) + 1(19) + 2(12) + 3(6) + 4(3) + 5(2) + 6(0) + 7(2) + 8(1) = 0 + 19 + 24 + 18 + 12 + 10 + 0 + 14 + 8 = 105. Divide by 60 to obtain the average: 105 ÷ 60 = 1.75.