Answer
$r_s\gt 0.657$: null hypothesis is rejected.
There is enough evidence to conclude that there is a positive association between income and commute time.
Work Step by Step
$H_0: X~and~Y~are~not~associated$ versus $H_1: X~and~Y~are~positively~associated$
See the picture.
$∑d_i^2=6.25+0+0+4+0+0.25=10.5
$
$r_s=1-\frac{6∑d_i^2}{n(n^2-1)}=1-\frac{6\times10.5}{6(6^2-1)}=0.700$
Critical value = 0.657
(According to Table XIV, for n = 6 and α(1) = 0.1)
Since $r_s\gt 0.657$, we reject the null hypothesis.
