What is the sum of 1 3/8 and 2 3/16

The triangles are similar. what is the value of x? show your work.

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?

Explain how you can use the associative property to evaluate (7x50)x4.