Apiggy bank contains nickels and dimes. there are 160 total coins valuing $10.50. think about a system of equations that can be used to represent the number of nickels and dimes and then think through using substitution to solve the system of equations. how many nickels are in the piggy bank? 99 1,090 110 1,100

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.