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
8) So remember the sum of all angles inside a triangle is equal to 180°. We first want to figure out the angle below the 110°.
A straight line is 180° so if we do 180 - 110 we get 70° therefore the angle below the 110° is 70°.
So we now know two angles in the triangle, 70° and 80°. Add these and we get 150°. Now we can determine the final angle (the one labelled (2x - 6)) which will be 30°.
So let’s make it into an equation:
2x - 6 = 30
Add 6 to both sides to isolate 2x:
2x = 36
Divide by 2 to get the value of x:
x = 18
10) Since the sum of all angles in a triangle is 180, and there are only 3 angles, we can determine A easily.
B = 10°
C = 160°
So to determine A:
180 - 160 - 10
Which gives us 10
Therefore A = 10°.
So the answers:
8) x = 18
9) A = 10°
I hope this helps you!!
Answer:
y =47.5.
Step-by-step explanation:
First eliminate the fractions by multiplying through by the LCM of 7 and 3 which is 21:
21* 6[y-2]/7-21*12 = 21*2[y-7]/3
18(y - 2) - 252 = 14(y - 7)
18y -36 - 252 = 14y - 98
18y - 14y = -98 + 36 + 252
4y = 190
y = 190/4
y = 47.5.
Answer:
x=13
Step-by-step explanation:
we can guess that the three angles are a linear pair and equal 180
in this case we can start writing a equation
x+105+62=180
now we can subtract both whole numbers from 180 but that takes longer, so we will combine the whole numbers on the left side.
x+167=180
now we can go ahead and subtract 167 from both sides. by doing so, it isolates the x and gives you your answer
180-167=13
so... x=13
O-O-T-O-T-T And I have calculated them
