Could someone please let me know what they got as the answer for this question:
A company selling vegetable seeds in packets of 40 estimates that the mean number of seeds that will actually grow is 36.0 with a standard deviation of 1.8 seeds. If a customer buys 9 different seed packets, what are the expected value and standard deviation of the number of bad seeds? Assume that packets are independent of each other.
a. μ = 108.00, σ = 16.2
b. μ = 324, σ = 5.40
c. μ = 108.00, σ = 5.40
d. μ = 324, σ = 145.8
e. μ = 324, σ = 16.2
Let X be the random variable number of good seeds in a packet. Then E(X) = 36.0 and var(X) = 1.8^2.
Originally Posted by Mike123
Let Y be the random variable number of good seeds in 9 packets. Then Y = 9X.
E(Y) = 9E(X) = ....
Var(Y) = 9^2 Var(X) => sd(Y) = 9 sd(X) = ....