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According to the number line, what is the distance between points a and b? v ++ + + + + -16 -14 -12 -10 -8 + 6 + 4 + -2 + 0 + 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 o6 units o 7 units 12 units o 14 units

Suppose a pendulum is l meters long. the time,t,in seconds that it tales to swing back and forth once is given by t=2.01

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?