So let me call this d for difference. And it is equal to the difference in height between a randomly selected man and a randomly selected woman. So d, the random variable d, is equal to the random variable m minus the random variable w. So the first two are clearly normally distributed. They tell us that right over here. The male and female heights are each normally distributed. And we also know, or you're about to know, that the difference of random variables that are each normally distributed is also going to be normally distributed. So given this, can you think about how to tackle this question?