Dr. Anderson found that 18 out of 30 children in the village tested positive for chicken pox. At this rate, how many would test negative if there were 70 children in the village as a whole

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

What is the slope of the line that contains the points (-2,1) and (0,-3)

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.