SOLUTION: A survey of 1000 people were asked whether they wear eyeglasses while driving. These people were also tested to see whether they need to wear eyeglasses while driving. 440 wear

Algebra ->  Probability-and-statistics -> SOLUTION: A survey of 1000 people were asked whether they wear eyeglasses while driving. These people were also tested to see whether they need to wear eyeglasses while driving. 440 wear       Log On


   

Question 1162349: A survey of 1000 people were asked whether they wear eyeglasses while driving.
These people were also tested to see whether they need to wear eyeglasses
while driving.
440 wear glasses and need to wear them
20 wear glasses and do not need to wear them
140 don't wear glasses but need to wear them
400 don't wear glasses and don't need to wear them
What is the probability that they wear glasses while driving even though they
do not need to wear them?
Answer by ikleyn(52798) About Me  (Show Source):
You can put this solution on YOUR website!
.

The question in this post 

    What is the probability that they wear glasses while driving even though they do not need to wear them?

is posed  INCORRECTLY,  since it does not define who are that  "they".


A  RIGHT  question should be 

    If a person is selected randomly from these 1000 people, 

    then what is the probability that he (or she) wears glasses while driving even though he (or she) does not need to wear them?

Then the answer,  as it is  OBVIOUS,  is   20%2F1000 = 1%2F50.

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Your post is fixed;  the problem is solved;  the question is answered and the solution is completed.