Calculate t-score and z-score below WITHOUT USING THE TABLES. PLEASE SHOW YOUR FORMULAS. The sample mean ?y??? of size n=15 is 8.1, sample standard deviation ?Sn?1?? is of size n=15 is 7.2.

n = 10 n = 15 n = 20 n = 40 n = 100 n = 400 Zo.975 1.960 ? ? . tn-1,0.975 2.145