Answer:
3.25 > 3 1/4 because 3 1/4 as a decimal is 0.75
2.5(x - 9) = 8
Distribute the 2.5
2.5x - 22.5 = 8
Add 22.5 to both sides
2.5x = 30.5
Divide both sides by 2.5
x = 12.2
Yes the probability of an outcome that lies within 68% is a good indicator that lies in which standard deviation.