An elevator of mass 250 kg is carrying two persons whose masses are 50 kg and 100 kg 1f the force exerted by the motor is 3000 N. Taking g as 10m/s calculate the total mass of
the bodies in the elevator.​

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error