A study considers if the mean score on a college entrance exam for students in 2005 is any different from the mean score of 501 for students who took the same exam in 1975. Let μ represent the mean score for all students who took the exam in 2005. For a random sample of 40,000 students who took the exam in 2005, x = 499 and s = 100.

(a) Find the test statistic.(b) Find the P-value for testing H0: μ = 501 against Ha: μ ≠ 501.