65 divided by 7 is approximently 9, and 25 divided by 7 is approximently 3, so 9 plus 3 is 12, so Gracie must wash 12 cars to earn enough money to save 25 and spend 65!
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
Vì tam giác ABC cân tại A (gt) mà AM là đg trung tuyến nên AM đồng thời là đg cao của t/giác đó:
AM là trung tuyến của t/giác ABC nên M là trung điểm BC:
=> BM =BC/2 =6:2=3(cm)
Xét tam giác AMB vuông tại M
AB^2 =AM^2+BM^2 ( theo định lý Py-ta -go)
Answer:
(-3, 3) and (8, -8)
Step-by-step explanation:
having the rule (x + 3, y – 5) and an input point (x,y) you just plu th iput point into the rule and you will get the output point.
With an input point (-6,8) you plug -6 in for x and 8 in for y into the rule.
(x + 3, y – 5)
(-6 + 3, 8 - 5)
(-3, 3)
Now we do the same for (5, -3) as the input
(x + 3, y – 5)
(5 + 3, -3 - 5)
(8, -8)
7 is a prime number, which means it can't be simplified. This fraction is already in simplest form, also because 25 and 7 don't have any common factors.
