56% enrolled if a same of 500 is randomly selected what probability 250 will get selected?

I'll get you started:

mean = np = (500)(.56) = ?

standard deviation = √npq = √(500)(.56)(.44) = ?

Note: q = 1 - p

Finish the calculations.

To find z-score:

z = (x - mean)/sd

Note: x = 250

Once you have the z-score, look in a z-table using the score to find your probability. Remember that the question is asking "at least 250" when looking at the table.