How do l find the mean, Variance of the following data; 10:2, 15:3, 7:2, 20:3

G(x)=x2-16xb=-16, so =16 = 649(x) = (x2 - 16x + 64) - 649(x) = (x - 1)2-

At the olympic games, many events have several rounds of competition. one of these events is the men's 100-meter backstroke. the upper dot plot shows the times (in seconds) of the top 8 finishers in the final round of the 2012 olympics. the lower dot plot shows the times of the same 8 swimmers, but in the semifinal round. which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a: the swimmers had faster times on average in the final round. b: the times in the final round vary noticeably more than the times in the semifinal round. c: none of the above.

Find the distance between the point (-3,-4), and (see the picture below)