A healthcare consultant wants to determine the difference in patient satisfaction ratings of two hospitals.
- Open the sample data, HospitalComparison.MTW.
- Choose .
- In Samples, enter Rating.
- In Sample IDs, enter Hospital.
- Click Options. Enter 1 in Base for random number generator.
Note
Using Base for random number generator ensures that your results match the example.
- Click OK in each dialog box.
Interpret the results
The 95% CI indicates that the consultant can be 95% confident that the difference in population means of the patient satisfaction ratings of two hospitals is between 14.4 and 27.6. The histogram shows that the bootstrap distribution appears to be normal, so the consultant can trust the results.

Bootstrapping for Difference in Means: Rating by Hospital
Bootstrap Histogram for Rating by Hospital
Observed Samples
Hospital N Mean StDev Variance Minimum Median Maximum
A 20 80.30 8.18 66.96 62.00 79.00 98.00
B 20 59.30 12.43 154.54 35.00 58.50 89.00
Difference in Observed Means
Mean of A - Mean of B = 21
Bootstrap Samples for Difference in Means
Number of 95% CI for
Resamples Average StDev Difference
1000 20.960 3.279 (14.400, 27.600)