Answer
$r_s\gt -0.571$: null hypothesis is not rejected.
There is not enough evidence to conclude that defense wins championships.
Work Step by Step
$H_0: X~and~Y~are~not~associated$ versus $H_1: X~and~Y~are~negatively~associated$
See the picture.
$∑d_i^2=0+4+0+4+16+4+4=32$
$r_s=1-\frac{6∑d_i^2}{n(n^2-1)}=1-\frac{6\times32}{7(7^2-1)}=0.429$
Critical value = -0.571
(According to Table XIV, for n = 7 and α(1) = 0.1)
Since $r_s\gt -0.571$, we do not reject the null hypothesis.
