What does the measure of BC equal? plz show your work

The difference of 2 numbers is 21 and the quotient of the equation is 4 then what are the two numbers?

Which of the following is the shape of a cross section of the figure shown below

Now max recorded the heights of 500 male humans. he found that the heights were normally distributed around a mean of 177 centimeters. which statements about max’s data must be true? a) the median of max’s data is 250 b) more than half of the data points max recorded were 177 centimeters. c) a data point chosen at random is as likely to be above the mean as it is to be below the mean. d) every height within three standard deviations of the mean is equally likely to be chosen if a data point is selected at random.