# Statistics Z Score (I think) Help?

1. Dec 8, 2011

### leggoma

1. The problem statement, all variables and given/known data

So my HW is

27. Assume the heights of high school basketball players are normally distributed. For boys the mean is 74 inches with a standard deviation of 4.5 inches, while girl players have a mean height of 70 inches and standard deviation 3 inches. At a mixed 2-on-2 tournament teams are formed by randomly pairing boys with girls as teammates.

a. On average, how much taller do you expect the boy to be?

b. What will be the standard deviation of the difference in teammates’ heights?

c. On what fraction of the teams would you expect the girl to be taller than the boy?

2. Relevant equations

Z=X-M/Std Dev (I think its relevant)

3. The attempt at a solution

I know how to do A and B. A is 74-70 and then for B you square the std devs, add them, and then take the sq root and end up getting about 5. But for Part C, I am kind of lost. Would I use a Z score chart Z=X-M/Std Dev or do I use a normalcdf or what?

Would I do normcdf(max, min, 4,5.1)? I don't see the max or min here though

Last edited: Dec 8, 2011