What is the probability that the reader is a young adult given that their favorite is Asimov or Brooks?

What is not true about kl and mn? what is mn? (show your work)

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%

Can someone tell me if this is perpendicular? !