Scores on the SAT test are normally distributed with a mean of 1518 and a standard deviation of 325. Scores on the ACT test are normally distributed with a mean of 21.1 and a standard deviation of 4.8. Assume that the two tests use different scales to measure the same aptitude.

a. If someone gets a SAT score that is the 67th percentile, find the actual SAT score and the equivalent ACT score.

b. If someone gets a SAT score of 1900, find the equivalent ACT score.