And so our null hypothesis is that beta is equal to zero. And the alternative hypothesis, which is her suspicion, is that the true slope of the regression line is actually greater than zero. Assume that all conditions for inference have been met. At the alpha equals 0.01 level of significance, is there sufficient evidence to conclude a positive linear relationship between these variables for all mobile phones, Y? So pause this video and see if you can have a go at it. Well, in order to do this hypothesis test, we have to say, well, assuming the null hypothesis is true, assuming this is the actual slope of the population regression line, I guess you could think about it, what is the probability of us getting this result right over here? And what we can do is use this information and our estimate of the sampling distribution of the sample regression line slope, and we can come up with a t-statistic.