Perceived Usefulness Rating(5-point Likert Scale)

PU01

PU02

PU03

...

I used SPSS to compute the mean of these data. The output as follow:

Descriptive Statistic N Minimum Maximum Mean Standard Deviation

PU01

PU02

PU03

Valid(listwise)

The result show that mean is compute for each PU01, PU02, PU03. This is not the result that I desired.

The question is how can I calculate the mean of the PU01, PU02, PU03 under a category which is Perceived Usefulness?

*English is not my native language.

Thank You.