Promethium has a half-life of 18 years. The equation A=200(12)1t can be used to find the amount, A, of promethium left after t years. Initially, there are 200 milligrams. Over the first 18 years, what is the average amount of promethium lost per year? Round your answer to the hundredths place.

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.