You are the Webmaster for your firm's Website. From your records, ...

[hubes95]

You are the Webmaster for your firm's Website. From your records, you know that the probability that a visitor will buy something from your firm is 0.23.
 
  If the number of visitors in one day is 952, what is the probability that less than 200 of them will buy something from your firm? Use the normal approximation for the binomial.

Question 2

How useful is the test in predicting good sales achievement?
 
  What will be an ideal response?

[jomama]

Answer to Question 1

n = 952, P = 0.23,  =E(X) = 218.96, 2 =Var(X) = nP(1 - P) = 168.5992,  = 12.985
P(X < 200 ) = P(Z < -1.46 ) = 0.0721

Answer to Question 2

Since, P(B  A ) = P(B ) = 0.30, events A and B are statistically independent (i.e., the occurrence of event A does not change the probability that B occurs), the test is not at all useful in predicting good sales achievement. An applicant has the same probability of good sales results regardless of whether or not the applicant showed high aptitude.

[hubes95]

Thanks for the timely response, appreciate it

[xiazhe]

Great answer, keep it coming