20 is what number of 400

An appliance salesman sets a goal to sell an average of 6 appliances per day for the first two weeks of his new job. the dot plot shows the number he sold each day during the first 13 days. what is the minimum number of appliances he must sell on the 14th day in order to reach his goal? a) 5 b) 6 c) 7 d) 8

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.

These tables represent a quadratic function with a vertex at (0, -1). what is the average rate of change for the interval from x = 9 to x = 10?