One-Sample T Test

This feature requires the Statistics Base option.

The One-Sample T Test procedure tests whether the mean of a single variable differs from a specified constant.

Examples. A researcher might want to test whether the average IQ score for a group of students differs from 100. Or a cereal manufacturer can take a sample of boxes from the production line and check whether the mean weight of the samples differs from 1.3 pounds at the 95% confidence level.

Statistics. For each test variable: mean, standard deviation, and standard error of the mean. The average difference between each data value and the hypothesized test value, a t test that tests that this difference is 0, and a confidence interval for this difference (you can specify the confidence level).

One-Sample T Test Data Considerations

Data. To test the values of a quantitative variable against a hypothesized test value, choose a quantitative variable and enter a hypothesized test value.

Assumptions. This test assumes that the data are normally distributed; however, this test is fairly robust to departures from normality.

To Obtain a One-Sample T Test

This feature requires the Statistics Base option.

  1. From the menus choose:

    Analyze > Compare Means > One-Sample T Test...

  2. Select one or more variables to be tested against the same hypothesized value.
  3. Enter a numeric test value against which each sample mean is compared.
  4. Optionally, click Options to control the treatment of missing data and the level of the confidence interval.

This procedure pastes T-TEST command syntax.