1. The mean value of the voltage,
2. The estimated error on this mean value δ V
3. You read one more value and the meter reads 5.003021 , what would you report for this value and error (on this one measurement)?

Hint: Unless you are really fast with a calculator, use a spreadsheet program (such as Excel) or statistical analysis program to read in and calculate the quantities you need.

Be sure to show your work and tell me what program you used.

1. Using Sigmaplot, PAW, or another plotting/fitting program of your choice...
   1. Make a histogram of the voltage data from Problem 1, found in this text file.
   2. Fit this data to a Gaussian distribution.
   3. Report the mean, sigma, and errors on these quantities.
   4. How are these related to the mean and standard deviation calculated in Problem 1?
2. You are measuring (with a Hall-probe gaussmeter) the magnetic field of our 12-inch electromagnet as a function of current supplied to the windings. You record the current, measured magnetic field, and estimated error on from the gaussmeter in this text file. The error on the current (the independent variable) is assumed negligible. Again, using a plotting/fitting program...
   1. Plot this data with error bars.
   2. Fit this data to a straight line (y=mx+b), show the fit, report the (two) fit parameters with errors.
   3. Report the "goodness-of-fit" parameter ("chisquare"). Does the data fit well to a straight line? Does this "chisquare" value tell you anything about these errors?

1. If you were not able to produce a histogram with variable binning in HW Set 2, either figure out how to get Sigmaplot to do it or use PAW. PAW is installed on 2 of the MPL computers (in small room). You can get help from within PAW by typing "help" or look on the www at: http://wwwinfo.cern.ch/asd/paw/index.html .
   1. (Re)make the histogram of the voltage data from Problem 1, found in this text file.
   2. Fit this data to a Gaussian distribution.
   3. Report the mean, sigma, and errors on these quantities.
   4. How are these related to the mean and standard deviation calculated in Problem 1?
   To help you get started in PAW, I have created this macro: make_hist.kumac . This will read the vector of voltage values, do the fit, plot, etc. In PAW: type "exec make_fit" to run it. You'll have to figure out how to put the files in the correct directories to see them.
2. Once again, you are measuring (with a Hall-probe gaussmeter) the magnetic field of our 12-inch electromagnet as a function of current supplied to the windings. You record the current, measured magnetic field, and estimated error on from the gaussmeter in this text file. (Note: this is a different file than in the previous problem) The error on the current (the independent variable) is assumed negligible. Again, using a plotting/fitting program...
   1. Plot this data with error bars.
   2. Fit this data to a straight line (y=mx+b), show the fit, report the (two) fit parameters with errors.
   3. Report the "goodness-of-fit" parameter ("chisquare"). Does the data fit well to a straight line? Does this "chisquare" value tell you anything about these errors?