How to add rational expressions with different denominators?

What are the first 4 terms in the multiplication pattern given by the formula 2×4n

Needmax 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.

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.