The average speed of a volleyball serve is 57 miles per hour. natalie practiced a new technique to improve her serving speed. her coach recorded the speed of 36 random serves during practice and found that her average speed using the new technique was 58.9 miles per hour, with a standard deviation of 2.8 miles per hour. part a: state the correct hypotheses if natalie is trying to prove the new technique is an improvement over the old technique. (4 points)part b: identify the correct test and check the appropriate conditions. (6 points)

Look at this system of equations. -3x + 3y = 12 y = x + 4 the solution set of this system is best explained by which of these statements? a) the graphs of the equations are the same line because the equations have the same slope and the same y-intercept. the system has infinitely many solutions. b) the graphs of the equations are parallel lines because they have the same slope but different y-intercepts. the system has no solution. c) the graphs of the equations are lines that intersect at one point because the equations have the same slope but different y-intercepts. the system has exactly one solution. d) the graphs of the equations are lines that intersect at one point because the equations have the same slope and the same y-intercept. the system has exactly one solution.