The data are given here as reported by Stigler. Stigler has applied the corrections used by Michelson and reports that the "true" value appropriate for comparison to these measurements is 734.5. Each trial may be a summary of several experimental observations.
Because the speed of light is a physical constant, we know (to a close approximation) the "true" value that Michelson was trying to measure. It is therefore possible to test the null hypothesis that the true mean = 734.5 for each of the trials or for all 100 determinations taken together.
There is evidence of trouble in the data. Boxplots of the trials side-by-side indicate that not all were equally variable nor even centered on the same value. A one-way ANOVA confirms this. One might consider startup effects and underlying bias in the instrument.