The sample mean is 17.17, and the standard deviation of these 10 data points right here is 2.98, the sample standard deviation. Does the data supply sufficient evidence to conclude that this type of engine meets the new standard? Assume we are willing to risk a type 1 error with a probability of 0.01, and we'll touch on this in a second. Before we do that, let's just define what our null hypothesis and our alternative hypothesis are going to be. Our null hypothesis can be that we don't meet the standards, that we just barely don't meet the standards, that the mean of our new engines is exactly 20 parts per million, and you essentially want the best possible value where we still don't meet, or the lowest possible value where we still don't meet the standard. Then our alternative hypothesis is no, we do meet the standard, that the true mean for our new engines is below 20 parts per million. To see if the data that we have is sufficient, what we're going to do is assume that this is true.