I need help because i don't understand math.

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.

Afamily went out to dinner and their bill was $113.if they want to leave a 19% tip, how much should they leave.

Roxanna earns 150% her normal hourly rate for overtime pay. last week, roxanna earned $72.00 in overtime pay for 4 hours. what is roxana's normal hourly pay?