Mcallister et al. (2012) compared varsity football and hockey players with varsity athletes from noncontact sports to determine whether exposure to head impacts during one season have an effect on cognitive performance. in the study, tests of new learning performance were significantly poorer for the contact sport athletes compared to the noncontact sport athletes. the following table presents data similar to the results obtained in the study. noncontact athletes: 10, 8, 7, 9, 13, 7, 6, 12contact athletes: 7, 4, 9, 3, 7, 6, 10, 2a. are the test scores significantly lower for the contact sport athletes than for the noncontact athletes? use a one-tailed test with \alpha=.05t-critical=t=b. compute the value of (percentage of variance accounted for) for these data. r^2= a. 0.123, b. 0.239, c. 0.138, d. 0.264

Asystem of linear equations with more equations than unknowns is sometimes called an overdetermined system. can such a system be consistent? illustrate your answer with a specific system of three equations in two unknowns. choose the correct answer below. a. yes, overdetermined systems can be consistent. for example, the system of equations below is consistent because it has the solution nothing. (type an ordered pair.) x 1 equals 2 comma x 2 equals 4 comma x 1 plus x 2 equals 6 b. no, overdetermined systems cannot be consistent because there are fewer free variables than equations. for example, the system of equations below has no solution. x 1 equals 2 comma x 2 equals 4 comma x 1 plus x 2 equals 12 c. yes, overdetermined systems can be consistent. for example, the system of equations below is consistent because it has the solution nothing. (type an ordered pair.) x 1 equals 2 comma x 2 equals 4 comma x 1 plus x 2 equals 8 d. no, overdetermined systems cannot be consistent because there are no free variables. for example, the system of equations below has no solution. x 1 equals 2 comma x 2 equals 4 comma x 1 plus x 2 equals 24