7. Correct. The answer is false.
T=( b - b)*(n-2)2/(sy.x/sx)=(0.636-0.454)*60.5/(0.5641/4.062)=3.2095
Since sy.x=0.5641 was computed in problem 8.4 and sx=(`x2-(`x)2)0.5=4.062 follows from problem 1.
On the basis of one-tailed t-test, we would reject the hypothesis that the regression coefficient is as low as 0.454 if t>t0.95=1.94 for 8-2=6 degrees of freedom. Thus we reject the hypothesis.