Lauren wants to know how many students in her school plan to see the new science fiction movie opening this weekend. She surveyed every Fitch student as they left the school on Friday. Population:

Sample:

Is this sample reprsentive? Explain.

Just to get point

The mean of these workers is total salary/number of workers=(5*25000+3*27000+1*34000)/(5+3+1)=26667, approximately. The standard deviation formula is \sqrt(1/n*sum of (x_i-mu)^2) from 1 to n. Plug in n=9, mu=26667, the standard deviation is 2915 dollars approximately.