Michelson Data on the Speed of Light
JMP: Version 5
Distributions: Speed

|
|
|
|
Mean |
299.8524 |
|
Std Dev |
0.0790105 |
Right click on the Moments in the Distribution output window. Select Make into Data Table. This should open up a new data table with two columns. The first column contains the names of the summary statistics and the second column contains the estimates. Double click on the Column 2 header. Rename the column Estimates and change the format to Fixed Decimal. Choose enough width (25 is sufficient for this problem) and enough decimal places (16 works here since the standard deviation has one leading zero and we want 15 places of accuracy).
|
|
Estimates |
Certified Value |
l=-log10[|q-c|/c] |
|
Mean, m |
299.8523999999999300 |
299.852400000000 |
lm = 15 |
|
Std Dev, s |
0.0790105478190506 |
0.0790105478190518 |
ls = 13.8 |
Round the Mean Estimate to 15 significant digits (299.852400000000). You are now ready to compare to the certified values.
Mean,
m: The Mean
Estimate produced by JMP agrees with the Certified value to 15 significant
digits. Therefore, lm = 15.
Std Dev, s: The Std Dev
Estimate produced by JMP disagrees with the Certified value in the last two
significant digits. Using JMP to
compute the lambda value, ls = 13.8.
Minitab: Version 13
Descriptive
Statistics: Speed
Variable N Mean Median TrMean StDev SE Mean
Speed 100 299.85 299.85 299.85 0.08 0.01
Variable Minimum Maximum Q1 Q3
Speed 299.62 300.07
299.80 299.90
Be sure to choose the standard deviation as well as the mean. Highlight the column that contains the mean and go to Editor – Format Column – Numeric. Select a Fixed Decimal with 12 digits. Change the column that contains the standard deviation to have a Fixed Decimal with 16 digits.
|
|
Estimates |
Certified Value |
l=-log10[|q-c|/c] |
|
Mean, m |
299.852400000000 |
299.852400000000 |
lm = 15 |
|
Std Dev, s |
0.0790105478190846 |
0.0790105478190518 |
ls = 12.4 |
Mean,
m: The Mean
Estimate produced by Minitab agrees with the Certified value to 15 significant
digits. Therefore, lm = 15.
Std Dev, s: The Std Dev
Estimate produced by Minitab disagrees with the Certified value in the last
three significant digits. Using Minitab
to compute the lambda value, ls = 12.4.
Enter
the data into the first column. Insert
functions for the AVERAGE and STDEV in appropriate cells. To get the correct number of digits use
Format – Cells – Number and choose 12 decimal places for the mean and 16
decimal places for the standard deviation.
|
|
Estimates |
Certified Value |
l=-log10[|q-c|/c] |
|
Mean, m |
299.852400000000 |
299.852400000000 |
lm = 15 |
|
Std Dev, s |
0.0790105482336454 |
0.0790105478190518 |
ls = 8.3 |
Mean, m: The Mean Estimate produced by
Excel agrees with the Certified value to 15 significant digits. Therefore, lm = 15.
Std
Dev, s: The Std Dev Estimate produced by Excel disagrees with the Certified
value starting with the eighth significant digit. Using Excel to compute the lambda value, ls
= 8.3.