This is a mean question. When identifying mean, you all all of the values up and divide by how many values are present. 2 + 3 + 5 = 10. 10 + x (which is 6) = 16. When you divide 16 by 4 (because 2, 3, 5, and x make 4 present values), you get 4 as the average. Therefore, your answer is x = 6.
