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Which of the following statements is not true? a. parallel lines are lines in the same plane that never intersect. b. congruent figures have the same shape and same size angles and sides. c. similar figures must have the same shape and the same size. d. a rotation is when you turn a figure around a certain point.

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?

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?