Refer to the chance (winter 2001) examination of sat scores of students who pay a private tutor to them improve their results. on the sat-mathematics test, these students had a mean change in score of 19 points, with a standard deviation of 65 points. in a random sample of 100 students who pay a private tutor to them improve their results. (a) what shape would you expect the sampling distribution of the sample mean for the sample of 100 students? any shape not symmetric bell-shape no pattern

If p(x) is the total value of the production when there are x workers in a plant, then the average productivity of the workforce at the plant is a(x) = p(x) x . (a) find a'(x). a'(x) = xp'(x) − p(x) x a'(x) = xp'(x) − p(x) x2 a'(x) = p'(x) − p(x) x a'(x) = xp'(x) − p'(x) x2 a'(x) = p'(x) − xp(x) x2 why does the company want to hire more workers if a'(x) > 0? a'(x) > 0 ⇒ a(x) is ; that is, the average productivity as the size of the workforce increases. (b) if p'(x) is greater than the average productivity, which of the following must be true? p'(x) − xp(x) > 0 p'(x) − xp(x) < 0 xp'(x) − p'(x) > 0 xp'(x) − p(x) < 0 xp'(x) − p(x) > 0

Asap! i need this done today and i really don’t understand it. some one ! will mark

Julia spends $5.25 on gas for her lawn mower. she earns $13.00 mowing her neighbor's yard. what is julia's profit?