(-4x⁴+6x²+3)-(5x²-3) answer should be a standard polynomial

Scale factor of 2 is used to enlarge a figure as shown below the area of is 18 in.²

Segment ab is shown on the graph. which shows how to find the x-coordinate of the point that will divide ab into a 2: 3 ratio using the formula

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.