A researcher wishes to study whether classical music has any effect on the ability to memorize information. A random sample of 63 adults were given a memory test in a quiet room. Then they were given a second memory test while listening to classical music. On the second test, 36 people received a higher score, 24 received a lower score, and 3 received the same score. A sign test at the 0.05 significance level will be used to test the claim that the music has no effect on memorization ability.

Required:
a. What is the value of the test statistic used in this sign test?
b. Give the value(s) of the critical value(s) used in this sign test. If there are two critical values, write them both with a comma between them.