P is a point inside a rectangle ABCD, where PA = 3, PC = 7 and PD = 6. Find PB.

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%