Assume that weights of men are normally distributed with a mean of 170 lb and a standard deviation of 30 lb. What percentage of individual men have weights less than 160 lb?

Assume that weights of men are normally distributed with a mean of 170 lb and a standard deviation of 30 lb.If samples of 49 men are randomly selected and the mean weight is computed for each sample, what percentage of the sample means are less than 160 lb?