Question

In july in seattle, the grass grows 1/2 inch a day on a sunny day and 1/4 inch a day on a cloudy day. in seattle, in july, 75% of the days are sunny and 25% of the days are cloudy.

a.find the expected value of grass growth for the day
b.find the expected value of grass growth for the month of july ( 31 days ) -- round both to 2 decimal placees

Answer 1

expected value equals sum of the product of each value and its possibility.
a.
1/2×75％＋1/4×25％=0.4375
the expected value of grass growth for the day is 0.4375
b.
0.4375×31=13.5625
the expected value of grass growth for the month of july is 13.5625