The second block gives the results of the t-test showing the t-score (2.255), degrees of freedom (19), One-sided p-value (.018), Two-sided p-value (.036), the mean difference between our scores and th...The second block gives the results of the t-test showing the t-score (2.255), degrees of freedom (19), One-sided p-value (.018), Two-sided p-value (.036), the mean difference between our scores and the hypothesized value, and finally, the 95% confidence interval. Well, since the t-test is basically a z-test with the assumption of known standard deviation removed, you shouldn’t be surprised to see that it makes the same assumptions as the z-test, minus the one about the known standard deviation.
We’re still assuming that the the population distribution is normal^[A technical comment… in the same way that we can weaken the assumptions of the z-test so that we’re only talking about the sampling...We’re still assuming that the the population distribution is normal^[A technical comment… in the same way that we can weaken the assumptions of the z-test so that we’re only talking about the sampling distribution, we can weaken the t test assumptions so that we don’t have to assume normality of the population.
