Solutions to Final Review

 

1.    a.    , then, solution is

 

       b.    , and break even is when Revenue = Cost, so solution is

 

 

2.    a.;       b.    ;       d.             e.    and solution is

 

3.    x = amount of dollars in tax-free bonds, y = amount in CD’s, z = amount in stocks

 

       then x + y + z = 80000, .075x + .08y + .11z = 7455, z = 2x

 

4.    a.    =

 

       b.   

 

5.    Can’t do here.

 

6.    Maximixe:     z = 40x + 30y, x = # of acres oranges, y = # of acres grapefruits

       Subj. To   :    x +  y  48

2x + y  80

                             x  0, y  0

 

       Max Profit = $1760 @ (32, 16)

 

7.    a.    A ∩ B = { 1, 5 }

 

b.        A’ È B = { 0, 1, 2, 5, 6, 8, 9 }

 

8.    a.    By addition rule P(A ∩ B) = P(A) + P(B) – P(A È B) = .09

 

b.        P(B|A) =  =

 

c.         No, A ∩ B Æ

 

9.    a.    P(F È R) = P(F) + P(R) – P(R ∩ F) =

 

b.        P(© first ∩© second) = P(© first) *P(© second | © first) =

 

10.         Can’t show diagram but we want P(Jar 2 | Red marble) =

 

      

 

11.  3!*7! = 30240

 

 

12.  a.    = 792

 

       b.   

 

13.  n = 8, p = 1/3, q = 2/3, x = 3:    P(x = 3) =  .273

 

14.  a.

X

0

1

2

P(X)

      

       X = # of green marbles,  probabilities found using combinations.

 

 

b.        E(X) = SX*P(X) =

 

15.  = 7.1          =   6.01