Do students tend to improve their SAT mathematics (SAT-M) score the second time they take the test? A random sample of four students who took the test twice received the following scores. Student 1 2 3 4 First Score 450 520 720 600 Second Score 440 600 720 630 Assuming that the change in SAT-M score (second score – first score) for the population of all students taking the test twice is Normally distributed with mean μ, a 95% confidence interval of μ is (hint: use Excel)