Parker is planning to build a playhouse for his sister. the scaled model below gives the reduced measures for width and height. hight 10 cm and base 22 cm. the yard space is large enough to have a playhouse that has a width of 3.5 meters. if parker wants to keep the playhouse in proportion to the model, what cross multiplication of the proportion should he use to find the height?

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.