Sam bought some shares in december 2010. in 2011 the value of the shares decreased by 20%.
in 2012 the value of the shares increased by 30%.
by what percentage did the value of the shares increase in the 2 years from the end of 2010 to the end of 2012?

Evaluate the expression for the given value of the variable. 5×(h+3) for h=7

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.

Starting at home, emily traveled uphill to the hardware store for 606060 minutes at just 666 mph. she then traveled back home along the same path downhill at a speed of 121212 mph. what is her average speed for the entire trip from home to the hardware store and back?