Answer:Given:
P(A)=1/400
P(B|A)=9/10
P(B|~A)=1/10
By the law of complements,
P(~A)=1-P(A)=399/400
By the law of total probability,
P(B)=P(B|A)*P(A)+P(B|A)*P(~A)
=(9/10)*(1/400)+(1/10)*(399/400)
=51/500
Note: get used to working in fraction when doing probability.
(a) Find P(A|B):
By Baye's Theorem,
P(A|B)
=P(B|A)*P(A)/P(B)
=(9/10)*(1/400)/(51/500)
=3/136
(b) Find P(~A|~B)
We know that
P(~A)=1-P(A)=399/400
P(~B)=1-P(B)=133/136
P(A∩B)
=P(B|A)*P(A) [def. of cond. prob.]
=9/10*(1/400)
=9/4000
P(A∪B)
=P(A)+P(B)-P(A∩B)
=1/400+51/500-9/4000
=409/4000
P(~A|~B)
=P(~A∩~B)/P(~B)
=P(~A∪B)/P(~B)
=(1-P(A∪B)/(1-P(B)) [ law of complements ]
=(3591/4000) ÷ (449/500)
=3591/3592
The results can be easily verified using a contingency table for a random sample of 4000 persons (assuming outcomes correspond exactly to probability):
===....B...~B...TOT
..A . 9 . . 1 . . 10
.~A .399 .3591 . 3990
Tot .408 .3592 . 4000
So P(A|B)=9/408=3/136
P(~A|~B)=3591/3592
As before.
Step-by-step explanation: its were the answer is
Answer:
6/21.
Step-by-step explanation:
let the rational number be 2x/7x.
2x + 4 / 7x - 2 = 10 /19
Cross multiply:
19(2x + 4) = 10(7x - 2)
38x + 76 = 70x - 20
96 = 70x - 38x
32x = 96
x = 3.
So the rational number is 2*3/ 7*3
= 6/21.
<u>Define x:</u>
Let Fred had x dollar.
Fred = x
Greg = x + 17
<u>Solve x :</u>
x + x + 17 = 85
2x + 17 = 85
2x = 68
x = 34
<u>Find the amount each of them had:</u>
Fred = x = $34
Greg = x + 17 = 34 + 17 = $51
Answer: Greg had $51
It typically just needs two parts
1) all parties must be in agreement
2) something of value needs to be exchanged. ie. money, a service
Answer:
A, C and E
Step-by-step explanation:
Simplify each expression to lowest terms. Equivalent expressions will be any expressions which are equal after simplifying to lowest terms.
A. -1/9 * 6 = -6/9 = -2/3
B. -15/10 = -3/2
C. 12/-18 = -2/3
D. -3/4 * 2/1 = -6/4 = -3/2
E. -8/9 * 3/4 = -24/36 = -2/3
