An equation that is equal to -3(x + 2)=-7

An animal shelter has 21 puppies. if the puppies are 28% of the total dog and cat population , how many dogs and cats are in the animal shelter

What are the sotions to the quadratic equation 9x^2=4

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.