David invested $220 in a savings account that offers a 3% return on the investment. the value of david's investment will be at least $400 after a period of years. hint: use the formula a = p(1 + r)t, where a is the amount after t years, p is the amount invested, r is the rate of interest, and t is the time period. use a calculator to compute the answer, and round it off to the nearest year.

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.