Answer
$X_0^2\gt X_α^2$: null hypothesis is rejected.
There is enough evidence to support the representative’s belief.
Work Step by Step
$H_0:~σ=0.05$ versus $H_1:~σ\gt0.05$
$X_0^2=\frac{(n-1)s^2}{σ_0^2}=\frac{(20-1)0.09^2}{0.05^2}=61.56$
Right-tailed test:
$n=20$
$d.f.=n-1=19$
$X_α^2=X_{0.05}^2=30.144$
(According to Table VII, for d.f. = 19 and area to the right of critical value = 0.05)
Since $X_0^2\gt X_α^2$, we reject the null hypothesis.
