And one standard deviation above the mean is going to be six centimeters above the mean. The standard deviation is six, six centimeters. So this would be minus six, is to go to one standard deviation below the mean. Now let's think about the difference between the two, the random variable d. So let me think about this a little bit. The random variable d, the mean of d is going to be equal to the differences in the means of these random variables. So it's going to be equal to the mean of m, the mean of m, minus the mean of w, minus the mean of w. Well we know both of these, this is gonna be 178 minus 170. So let me write that down.