statistics
posted by Anonymous .
About 24% of all homes purchased on 2004 were considered investment properties. a random sample of 800 homes sold in 2004 is obtained. What is the probability that at most 200 homes are used as an investment property?

Mean = np = 800 * .24 = ?
Standard deviation = √npq = √(800)(.24)(.76) = ?
Note: q = 1  p
Use zscores:
z = (x  mean)/sd
x = 200
Use a ztable to determine the probability. Remember the question is asking "at most 200" when looking at the table.
I'll let you finish the calculations. 
I get either 0.9099, 0.9103, or 0.9106