physics qmhelp please

Question

1. Student A performs a similar experiment with a different object and obtains the following direct measurements of the mass of their object: [21.06g, 20.98g, 21.12g, 21.21g, 21.10g]
2. a. Calculate and report the average, standard deviation, and standard error of Student A’s mass measurements using the 1D Stats macro.
3. b. Add one gram to each of the five mass values in part (a). Repeat your 1D Stats calculation and report the average, standard deviation, and standard error. Which values have changed and which have not? Be sure to show your work, including the new 1D Stats results. The one gram difference in each measurement represents a systematic error in the data.
4. c. Change the masses back to their original values and now add a 10 gram systematic error to the first two values only. Repeat your 1D Stats and note what has and has not changed.

Answer 1

This is a statistics question. You should be able to calculate the average, std deviation and standard error of the mean if you simply follow the directions in the question. The resulting table should have the following numbers:

Looking at the bottom three rows you should be able to see for yourself what values change when you add a systematic 1g error to all datapoints, or when you add a systematic error of 10g to only two datapoints.

The point of this exercise is for you to understand that a fixed amount of systematic error will change the mean value but you have no way to know that a systematic error is present in your measurements (if no one told you). The std dev and std err remain unchanged.

If, on the other hand, there were only a couple of datapoints which had a systematic error in them, then the larger std dev and std err values give you a warning that perhaps you need to check why some of the measurements look so different from the others.

Hope this makes it clearer.