Complete parts (a) through (c) below. (a) Determine the criticalvalue(s) for aright-tailed test of a population mean at the =0.10 level of significance with 15 degrees of freedom. (b) Determine the criticalvalue(s) for aleft-tailed test of a population mean at the =0.01 level of significance based on a sample size of n=10. (c) Determine the criticalvalue(s) for atwo-tailed test of a population mean at the =0.01 level of significance based on a sample size of n=12.

(a) t crit= _________(Round to three decimal places asneeded.)

(b) t {Subscript crit}=_________(Round to three decimal places asneeded.)

(c) t {Subscript crit}= _________( Round to three decimal places as needed.)