And so if we think about a t-distribution, I'll try to hand-draw a rough t-distribution really fast, and if this is the mean of the t-distribution, what we are curious about, because our alternative hypothesis is that the mean is less than 18, so what we care about is, well, what is the probability of getting a t-value that is more than 1.9 below the mean? So this right over here, negative 1.9. So it's this area right there. And so I'm gonna do this with a TI-84, at least an emulator of a TI-84, and all we have to do is we would go to second distribution and then I would use the t-cumulative distribution function. So let's go there, that's the number six right there, click Enter. And so my lower bound, yeah, I essentially want it to be negative infinity, and so we can just call that negative infinity, it's an approximation of negative infinity, very, very low number. Our upper bound would be negative 1.9, negative 1.9.