4.5 - Bootstrapping in Minitab Express
In this lesson you have learned how to construct bootstrap confidence intervals using StatKey. Minitab Express can also be used to construct bootstrap confidence intervals for a single mean, a single proportion, or the difference between two independent means using the percentile method. Below are two examples.
MinitabExpress – Bootstrap Confidence Interval for a Proportion
To construct a 95% bootstrap confidence interval for the proportion of students who smoke cigarettes:
- Open the data set:
- On a PC: Select Statistics > Resampling > Bootstrapping > 1-Sample Proportion
On a Mac: Select Statistics > Resampling > Bootstrapping for 1-Sample Proportion - Double click the variable Smoke Cigarettes in the box on the left to insert the variable into the Sample box
- Use the largest number of resamples, 1000
- Click on the Options tab
- The default is a Two-sided confidence interval at the 95% confidence level
- Click OK
This should result in output similar to the output below. Note that your results may be slightly different due to random sampling variation.
Variable | N | Proportion |
---|---|---|
Smoke Cigarettes | 226 | 0.07522 |
Number of Resamples | Average | 95% CI for Proportion |
---|---|---|
1000 | 0.07645 | (0.04425, 0.11062) |
Select your operating system below to see a step-by-step guide for this example.
MinitabExpress – Bootstrap Confidence Interval for a Mean
To construct a 95% bootstrap confidence interval for the mean GPA:
- Open the data set:
- On a PC: Select Statistics > Resampling > Bootstrapping > 1-Sample Mean
On a Mac: Select Statistics > Resampling > Bootstrapping for 1-Sample Mean - Double click the variable GPA in the box on the left to insert the variable into the Sample box
- Use the largest number of resamples, 1000
- Click on the Options tab
- The default is a Two-sided confidence interval at the 95% confidence level
- Click OK
This should result in output similar to the output below. Note that your results may be slightly different due to random sampling variation.
Variable | N | Mean | StDev | Variance | Sum | Minimum | Median | Maximum |
---|---|---|---|---|---|---|---|---|
GPA | 226 | 3.23106 | 0.51040 | 0.26050 | 730.220 | 0.00000 | 3.30000 | 4.00000 |
Number of Resamples | Mean | StDev | 95% CI for \(\mu\) |
---|---|---|---|
1000 | 3.23288 | 0.03330 | (3.16261, 3.29863) |
Select your operating system below to see a step-by-step guide for this example.
Note: When using StatKey you were told to take at least 5,000 resamples. Unfortunately, at this time Minitab Express will only take a maximum of 1,000 resamples at a time. For this reason your results may vary more in Minitab Express than in StatKey.