What is the probability that the man doesn't work and the woman ...

[craiczarry]

What is the probability that the man doesn't work and the woman works?
 
  What will be an ideal response?

Question 2

For a particular aptitude test, the mean score was 83.2. Suppose you were told that your score of 87 placed you in the 85th percentile. Assuming the data is bell-shaped, provide an estimate of the standard deviation of the test.
 
  What will be an ideal response?

[Joy Chen]

Answer to Question 1

P(both man and woman are not working) = 1 - 0.88 = 0.12
P(woman doesn't work  man doesn't work) = 0.40
P(man does not work) = P(both man and woman are not working)/0.40
= 0.12/0.40 = 0.30
P(man does not work) = P(man doesn't work and woman doesn't work)+
P(man doesn't work and woman works)
Then, 0.30 = 0.12 + P(man doesn't work and woman works)
Hence, P(man doesn't work and woman works) = 0.30 - 0.12 = 0.18

Answer to Question 2

At the 85th percentile, you outperformed more than 68 of the class, so we know that you scored more than 1 standard deviation above the mean. Therefore the standard deviation must be less than 87 - 83.2 or 3.8 points.

[craiczarry]

Thank you

[Joy Chen]

No problemo