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: =−q+48.929073 <-- coming frm a calculator lol
Step-by-step explanation:
Answer:
210 ways
Step-by-step explanation:
In the question, the combination should be computed.
Number of ways of selection 6 flowers = nCr =10C6
=
=3628800/17280
=210
Therefore, there are 210 ways in which 6 flowers can be selected from the available 10 flowers.
Answer:
Step-by-step explanation:
5x=y+6 --------- equ 1
2x-3y=4 -------- equ 2
5x - 6 = y
y = 5x - 6
substitute in equ 2
2x-3(5x - 6) =4
2x - 3*5x + 3*6 = 4
2x - 15x + 18 = 4
- 13x = 4 - 18
-13x = -14
x = -14/-13
x = 14/13
substitute in equ 1
5*14/13 = y+6
70/13 - 6 = y
y = ( 70 - 78)/13
y = -8/13