In: Statistics and Probability
A farmer knows from experience that his wheat harvest Q (in
bushels) has the probability distribution given by:
Q = 150 with probability 0.30 ,
= 170 with probability 0.45,
=200 with probability 0.25;
note that the probabilities add up to 1 as they are required by a probability
distribution. Suppose the demand function he faces in the market place is given by:
p = 320 - 0.5 Q
where p = price in dollars per bushel. Let R = total revenue = p x Q. [Note: You may find it
convenient to first derive the probability distribution of R.]
(i) (6 points). Find E ( R ).
Also, define his Profits as :
Profits = R - C ,
where the total cost C (in dollars) is a function of Q given by
C = 150 - 10 Q + 2 Q2.
(ii) ( 9 points). Find E(Profits).
(d) ( 6 points).Suppose you know the values of : Mean = E ( X ) and Variance = V(X) of a
variable X in a given population. Indicate how you will construct T1 and T2 such that
P( T1 < Xf < T2 ) = 0.9 (approximately),
where Xf is the value of X you will observe on the individual you will draw randomly from the population. Assume that you know X0 ≠ Xf , which is a realized value of X. [Do not assume that X is normal.]