11. Agriculture: Grapefruit It is estimated that 75% of a grapefruit crop is good;

the other 25% have rotten centers that cannot be detected until the grapefruit are cut open. The grapefruit are sold in sacks of 10. Let r be the number of good grapefruit in a sack.

(a) Make a histogram of the probability distribution of r.

(b) What is the probability of getting no more than one bad grapefruit in a sack?

What is the probability of getting at least one good grapefruit in a sack?

(c) What is the expected number of good grapefruit in a sack?

(d) What is the standard deviation of the r-probability distribution?