A marble is fired horizontally with an initial velocity of 2.5 m/s from a table that is 0.8 m high. How far will the marble travel along the floor before it lands?

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