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:
18%
Step-by-step explanation:
Long Version: 41/50 = 0.82 and when you move the decimal two places right, you will get 82%. 100%-82%= 18%
Short Version: 9/50 people didn't like perfume. 9/50= 0.18 then you move the decimal two places right and it becomes 18%.
Answer:
Step-by-step explanation:
Multiply the equations together
(5x+4)(5x^2-7x-2)
25x^3-35x^2-10x+20x^2-28x-8
Add like terms
25x^3-15x^2-38x-8
7/6
it’s positive because it’s going up
Answer:
y = 3x - 14
Step-by-step explanation:
Perpendicular lines will have a opposite reciprocal slope, so the slope will be 3.
Plug in the slope and given point into y = mx + b, then solve for b:
y = mx + b
4 = 3(6) + b
4 = 18 + b
-14 = b
Plug in the slope and y intercept into y = mx + b
y = 3x - 14
So, the equation of the line is y = 3x - 14
