One way of doing this is to write the equation of ratios (15 screwdrivers / 45 screwdrivers) = ($300 / x). Solve this equation for x. To do this, you might try multiplying both sides of this equation by x to eliminate fractions.
Another way is to obtain the unit cost of each screwdriver and then multiply the result by 45 screwdrivers.
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:
option B.
About 16% of the books have fewer than 150 pages
Step-by-step explanation:
Since we are dealing with a normal distribution
68.27% of the values will fall in the range with the standard deviation
(180-30 , 180+30) = (150, 210)
Approximately 15.86% of the values will be higher than 210
and the rest 15.86% will be lower than 150
So the correct answer is option B.
About 16% of the books have fewer than 150 pages
Answer:
Do in calculator simple answer
Answer:
Step-by-step explanation:
opp=x,hyp=10
sin 53°=
cross multiply
sin 53° x 10 =x
0.7986 x 10=x
7.98=x
x≅ 8.0
