question related to statistics (please, urgent)

Question

1. Decide whether the numerical value describes a parameter or a statistic.

 

“Starting salaries for all MBA graduates from the School of Business, University of Eriz increased 85% from the previous year”
2. If P(A bar) = 0.662, what is the value of P(A)? 3. If P(A) = 0.7, P(B) = 0.1, and A and B are mutually exclusive, find P (A or B).
4. The mean of a data set is 4.68 and its standard deviation is 2.83. Find the z-score for the value 9.83. Find the z-score for which the area to its left is 0.54.

Answer 1

2. If P(A bar) = .662 the P(A) = .338    1-P(A) = P(A bar)

 

3. Just add since Mutually Exclusive, .7+.1 =.8

 

4. z-score:  (9.83-4.68)/2.83 = 1.819  

 

Your last question depends on the shape of the distribution. I will assume it is normal.

 

ANSWER: .1004337118   (looked up on a normal z-chart)