These are just two ways of phrasing the same thing. Now, we know that the mean of the sampling distribution is the same thing as the mean of the population distribution, which is the same thing as the parameter p, the proportion of people, or the proportion of the population that is a one. This right here is the same thing as the population mean. This statement right here, we can switch this with p. The probability that p is within two standard deviations of the sampling distribution of x is 95.4%. Now, we don't know what this number right here is, but we have estimated it. Remember, our best estimate of this is the true standard, or it is the true standard deviation of the population divided by 10. We can estimate the true standard deviation of the population with our sampling standard deviation, which was 0.5, 0.5 divided by 10.