Question

A medical screening program administers three independent fitness tests. Of the persons taking the tests, 85% pass test 1, 65% pass test 2, and 50% pass test 3. A participant is chosen at random

a) What is the probability that she will pass all 3 tests?
b) What is the probability that she will pass at least 2 of the 3 tests?

Answer 1

prob of passing test 1 = 0.85
prob of passing test 2 = 0.65
prob of passing test 3 = 0.65

Answer 2

here the events are all independent so just multiply the individual probabs for part (a)

Answer 3

multiply all 3 together?

Answer 4

yup

Answer 5

okay i got .27625 for that!

Answer 6

ok

Answer 7

how do i find the second?

Answer 8

can you say the probab of not passing test 1

Answer 9

prob of passing test 1 = 0.85 hence prob of not passing test 1 is 1-0.85 =0.15
and similar for the rest tests

Answer 10

so do i find all of those and use them together?

Answer 11

u need to find them but also check what the question asks

Answer 12

hint :
prob for passing test 2 and test3 and not tets1 = 0.65*0.5*0.15 =0.04875

Answer 13

1-0.04875?

Answer 14

nope
find the probab for apssing test1 and 3 and not test2
find the probab for apssing test1 and 2 and not test3

Answer 15

ahh okay hold on

Answer 16

not passing test 2 would be .35*.85*.5= .14875
not passing test 3 would be .5*.85*.65= .27625

Answer 17

probability that she will pass at least 2 of the 3 tests
= (prob for passing test 2 and test3 and not tets1) + (probab for apssing test1 and 3 and not test2)+ (probab for apssing test1 and 2 and not test3) + probability that she will pass all 3 tests

Answer 18

.75?

Answer 19

?