So this is the sampling distribution. It will have a mean. And now, if we assume the null hypothesis, that the drug has no effect, the mean of our sampling distribution will be the same thing as the mean of the population distribution, which would be equal to 1.2 seconds. Now, what is the standard deviation of our sampling distribution? The standard deviation of our sampling distribution should be equal to the standard deviation of the population distribution divided by the square root of our sample size, so divided by the square root of 100. We do not know what the standard deviation of the entire population is. So what we're going to do is estimate it with our sample standard deviation.