At a certain middle school, there are 200 5th graders, 220 6th graders, 180 7th graders, and 150 8th graders. The Dean of Students chooses a scholar at random to help run Community Circle. What is the probability that a 7th grader is chosen?

Aci is desired for the true average stray-load loss μ (watts) for a certain type of induction motor when the line current is held at 10 amps for a speed of 1500 rpm. assume that stray-load loss is normally distributed with σ = 2.3. (round your answers to two decimal places.)