When you specify a test difference of zero – in other words, when the null hypothesis states that the two proportions are equal, Minitab performs Fisher's exact test in addition to a normal approximation test. This test is valid for all samples, regardless of the number of events or trials in each sample.

For the student employment data, Fisher's exact test calculated a p-value of 0.000. Minitab rounds p-values to three decimal points, so you conclude that the actual p-value is less than 0.0005. This p-value is lower than common a-levels, so you can reject the null hypothesis that the proportions of male and female students with summer employment are equal.