Answer:
a) 0.2416
b) 0.4172
c) 0.0253
Step-by-step explanation:
Since the result of the test should be independent of the time , then the that the test number of times that test proves correct is independent of the days the river is correct .
denoting event a A=the test proves correct and B=the river is polluted
a) the test indicates pollution when
- the river is polluted and the test is correct
- the river is not polluted and the test fails
then
P(test indicates pollution)= P(A)*P(B)+ (1-P(A))*(1-P(B)) = 0.12*0.84+0.88*0.16 = 0.2416
b) according to Bayes
P(A∩B)= P(A/B)*P(B) → P(A/B)=P(A∩B)/P(B)
then
P(pollution exists/test indicates pollution)=P(A∩B)/P(B) = 0.84*0.12 / 0.2416 = 0.4172
c) since
P(test indicates no pollution)= P(A)*(1-P(B))+ (1-P(A))*P(B) = 0.84*0.88+ 0.16*0.12 = 0.7584
the rate of false positives is
P(river is polluted/test indicates no pollution) = 0.12*0.16 / 0.7584 = 0.0253
Get n to one side
-1/5=-2/5n
divide both sides by -2/5
n=1/2
1. 13/3m
2. 24m to the 2nd power over 3 m
3.72 m to the 2nd power -11 over 3m
4.-16/3m
Answer:
B. 30
Step-by-step explanation:
First, you multiply by 5 from both sides of equation.
Simplify, to find the answer.
, which is our answer.
Step-by-step explanation:
3y + x = 12
When y = 3, we have 3(3) + x = 12.
=> 9 + x = 12, x = 3.
