For a 4-unit class like Statistics, students should spend average of 12 hours studying for the class. A survey was done on 21 students, and the distribution of total study hours per week is bell-shaped with a mean of 12 hours and a standard deviation of 2.6 hours.

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.

[15 points]find the least common multiple of the expressions: 1. 3x^2, 6x - 18 2. 5x, 5x(x +2) 3. x^2 - 9, x + 3 4. x^2 - 3x - 10, x + 2 explain if possible

Which sums are equal to 1hold 6/8? choose all answers that are correcta.1/8+6/8b.12/8+2/8c.8/8+1/8+1/8+1/8+1/8+1/8+1/8d.8/8+6/8