(a) Determine the critical value(s) for a right-tailed test of a population mean at the \(\alpha=0.01\) level of significance with 15 degrees of freedom.

(b) Determine the critical value(s) for a left-tailed test of a population mean at the \(\alpha=0.10\) level of significance based on a sample size of \(n=10\).

(c) Determine the critical value(s) for a two-tailed test of a population mean at the \(\alpha=0.01\) level of significance based on a sample size of \(n=14\).