Un cuadro está sostenido por medio de dos cuerdas, tal y como se muestra en la figura. Si la resistencia a la tensión máxima de cada una de las cuerdas es de 10 lb, ¿cuál será el peso máximo en lb del cuadro para que las cuerdas no se rompan?

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.