If the sample standard deviation is 10.5 and the sample mean is 48 based on a study with a sample size of 120, the 95 percent confidence interval about the mean is between approximately _____.
a.44.37 and 51.63
b.46.12 and 49.88
c.47.88 and 48.12
d.40.0 and 50.0
Answer: B: 46.12-49.88