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
Answer:
Step-by-step explanation:--0.9
Answer:
y=-x+3.
Step-by-step explanation:
The graph goes down one and right one before making another point. This means that the slope is -1/1. Simplify and you get -1. So far we have y=-1x. -1x is the same as -1. Now we have y=-x. The graph intersects the y-axis at the point (0,3). This makes our y-intercept 3. Our final equation is y=-x+3.
Answer:
3 and 9
Step-by-step explanation:
The factors of 18 can be listed as
1, 2, <u>3</u>, 6, <u>9</u>, 18
The two which sum to 12 are 3 and 9
