CPhill

Very nice, Erlich  and Guest.........!!!

                           Algebra                Not in Algebra         Total

Chemistry               6                          6                          12

Not in Chemistry    11                        17                         28

Total                       17                        23                         40

Part A   

N(Algebra or Chemistry)  = N(Algebra) + N(Chemistry)  - N(Algebra and Chenistry)  =

                                                17          +     12                                    6                     =     23

Part B  

Just chemistry  =  (6/40)*2000  =   300

Part A  with replacement  =   4/52 * 4/52  =  16/ 2804   =  1 / 169

Part B without replacement  =  13/52  * 13/51   you are correct   FWAS....!!!....just do the math, now!!!

The second is dependent......the probability of drawing a spade on the second draw might be either 13/51 or 12/51    depending on what card is drawn first...... 

Let H  = P(Honor roll)  =.30

Let J = P(Part-time Job)  = .70

P ( H and J)  =   .25

We want to find

P (H l J )   =    P(H and J)  / P(J)   =     .25  /  .70    =   .357   ≈   36 %

P( 41-55  or Disney World)  = P(41-55)  + P(Disney World)  - P(41-55 and Disney World)

P( 41-55  or Disney World)  =   .36         +       .42                  -         .11    

 =    .67   =  67%

We could draw the 3 first and then the 7.....or we could draw the 7 first and then the 3....so...

P(drawing the first card) =  4/52  .....P(drawing the second card)  = 4/51

And we can do this in 2 ways  "7" first and then "3"  or vice-versa

2 (4/52) (4/51)   = 2(1/13)(4/51)  =  8/663

These are definitely dependent events

Notice asinus, that  for  (4,5) , y =  -x + 9    is correct

But....for   (-2, - 7)    we have that   f(-2)  =  - (-2) + 9   =  11    which is incorrect

Let B  = Probability of buying a car and being male    21/88

Let M = Probability of being a male  =  48/88 

P(B l M)   =  P(B and M) / P(M)   =   (21/88) / (48/88)  = 21/48  = .4375  = 44%

Translation......we wish to write the equation of a line in the form y = mx + b given the points (4, 5)  and (-2, -7)

First.....find the slope  =   [subtract y's in some order] / [ subtract x's in the same order]

So we have

[ -7 - 5] / [ -2 - 4]  =  -12/ -6    = 2

And using either point ....the point-slope form becomes

y = 2(x - 4) + 5  simplify

y = 2x - 8  + 5

y = 2x  - 3

We have that

P(LC l S )  =  P( LC and S) / P(S)

.205   =  P(LC and S) / .39        multiply both sides by 39

(.39) (.205)  = P(LC and S)   =  .07995 ≈ .08