On the coordinate plane shown, each grid unit represents 10 feet. Polygon QRST has vertices Q(10, 30), R(−20, 30), S(−20, −10), and T(10, −10), and represents the floor plan of a room. Find the perimeter and area of the room.

The life (in hours) of a magnetic resonance imagining machine (mri) is modeled by a weibull distribution with parameters β = 2 and δ = 370 hours. (a) determine the mean life of the mri. (round your answer to 2 decimal ) determine the variance of the life of the mri. (round your answer to 1 decimal ) what is the probability that the mri fails before 250 hours? (round your answer to 4 decimal places.)