Twenty-five people, including yourself, are to measure the length of a room to the nearest tenth of a millimeter. Assume that everyone uses the same well-calibrated measuring device, such as a tape measure.

a. All 25 measurements are not likely to be exactly the same; some will be higher than the true value and some lower. Do these differences represent systematic or random errors? Explain.

b. If you want to minimize the effect of random errors in determining the length of the room, which is the better choice: to report your own personal measurement as the length of the room or to report the mean (average) of all 25 measurements? Explain.

c. Describe any possible sources of systematic errors in the measurement of the room length.

d. Can the process of averaging all 25 measurements help reduce any systematic errors? Why or why not?