3.4. The answers to the missing numbers are in boxes: Y, = -66.1058 + 0.0650 X r2 = 0.9460 se = (10.7509) (0.0035 ) n = 20 1 = (-6.1489 ) (18.73) The critical t value at the 5% level for 18 d.f. is 2.101 (two-tailed) and 1.734 (one-tailed). Since the estimated t value of 18.73 far exceeds either of these critical values, we reject the null hypothesis. A two-tailed test is appropriate because no a priori theoretical considerations are known regarding the sign of the coefficient