Here is computer output on the sample data. So we have some statistics calculated on the reaction time, on the memory time, and then he had his computer do a regression for the data that he collected, and then we're told assume that all conditions for inference have been met, calculate the test statistic that should be used for testing a null hypothesis that the population slope is actually zero. So pause this video and have a go at it. All right, so let's just make sure we understand what is going on. So let's first think about the population. So I'll do that right over here. So in the population, there might be some true linear relationship.