The repair bill, y, of a car is proportional to x, the number of labor hours. The constant of proportionality is 42.50. Which will check that y is proportional to x?
Graph y=42.50 x and check that the graph is a straight line that goes through (0,0)
Graph x=42.50 y and check that the graph is a straight line that goes through (0, 0)
Graph y=42.50 x and check that the graph is a straight line that goes through (1, 0)
Graph y= 42.50 x and check that the graph is a straight line that goes through (1, 40)

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.