7
a librarian estimated that the library had 65 books about george
washington and 80 books about abraham lincoln. the library actually has
67 books about washington and 71 books about lincoln,
to the nearest whole percent, what is the percent error of the librarian's
total estimate? write your answer in the box.

The longer leg of a 30° 60° 90° triangle is 16 times square root of three how long is a shorter leg

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

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.