Expectation is computed by multiplying each outcome (number of hybrids sold) by the corresponding probability, then adding these products:
0×0.32 + 1×0.28 + 2×0.15 + 3×0.11 + 4×0.08 + 5×0.06
= 1.53
So on average, 1.53 hybrids are sold each week.
