Complete parts ​(a) through ​(c) below. ​(a) Determine the critical​ value(s) for a​ right-tailed test of a population mean at the alphaequals0.05 level of significance with 10 degrees of freedom. ​(b) Determine the critical​ value(s) for a​ left-tailed test of a population mean at the alphaequals0.01 level of significance based on a sample size of nequals20. ​(c) Determine the critical​ value(s) for a​ two-tailed test of a population mean at the alphaequals0.01 level of significance based on a sample size of nequals11. LOADING... Click here to view the​ t-Distribution Area in Right Tail. ​(a) t Subscript critequals ▼ plus plus or minus minus nothing ​(Round to three decimal places as​ needed.) ​(b) t Subscript critequals ▼ plus or minus plus minus nothing ​(Round to three decimal places as​ needed.) ​(c) t Subscript critequals ▼ minus plus plus or minus nothing ​(Round to three decimal places as​ needed.)