Suppose that B1 and B2 are mutually exclusive and complementary ...

[ahriuashd]

Suppose that B1 and B2 are mutually exclusive and complementary events, such that P(B1 ) = .6
  and P(B2 ) = .4. Consider another event A such that P(A  B1 ) =.2 and P(A  B2 ) = .5. Find P(B1
 
  A).
  A) .375 B) .800 C) .625 D) .240

Question 2

A standardized test has a mean score of 500 points with a standard deviation of 100 points. Five
  students' scores are shown below.
 
  Adam: 575 Beth: 690 Carlos: 750 Doug: 280 Ella: 440
  Which of the students have scores within two standard deviations of the mean?
  A) Adam, Beth B) Adam, Beth, Carlos, Ella
  C) Carlos, Doug D) Adam, Beth, Ella

[duy1981999]

Answer to Question 1

A

Answer to Question 2

D