Complete parts (a) through (c) below.

(a) Determine the criticalvalue(s) for aright-tailed test of a population mean at the =0.01 level of significance with 20 degrees of freedom.

(b) Determine the criticalvalue(s) for aleft-tailed test of a population mean at the =0.10 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 =0.10 level of significance based on a sample size of n=13.

(a) tcrit= -, , or +___ (Round to three decimal places asneeded.)

(b) tcrit= -, , or +___ (Round to three decimal places asneeded.)

(c)tcrit= -, , or +___ (Round to three decimal places asneeded.)