The T-value is going to be equal to the difference between her sample mean and the assumed, the assumed population mean from the null hypothesis, that's what this little sub zero means, it means it's the assumed mean from the null hypothesis, divided by our estimate of the standard deviation of the sampling distribution. I say estimate because unlike when we were dealing with proportions, with proportions we can actually calculate the assumed based on the null hypothesis, sampling distribution standard deviation, but here we have to estimate it. And so it's going to be our sample standard deviation divided by the square root of N. Now in this example, they calculated all of this for us. They said, hey, this is going to be equal to 2.75. And so we can just use that to figure out our P-value. But let's just think about what that is asking us to do. So the null hypothesis is that the mean is zero.