Question 6.443

21.Math Scores. The National Assessment for Educational Progress reports that mean scores on the standardized math test for eighth-graders in 2013 was

.
  1. Find the probability that the test score of a randomly selected eighth-grader was greater than 178.
  2. What proportion of test scores was between 153 and 178?
  3. Suppose students who scored at the 5th percentile or lower could not graduate. Find the 5th percentile test score.
  4. Suppose you know someone who scored 188 on the test. Is this unusual? On what do you base your answer?

6.99.21

(a) 0.0062 (b) 0.4938 (c) 136.55 (d) Yes; .