You wish to test H0: σ =8.35 against HA: σ≠ 8.35, α = 0.05, and you obtain a simple random sample with n = 18, x = 104.7 and s = 10.41 from a population known to be normally distributed. Don't do the entire test (a) the critical value(s) and (b) the calculated (observed) value of the Chi-square test about σ
(NB. The x should have a bar on top of it. I didn't know how to get it there).