Solution
= Solution
Squaring each seasonal <standard deviation> gives the seasonal <variance> in squared concentration units:
* Winter: \b[$3.29^2=10.8241$].
* Spring: \b[$3.22^2=10.3684$].
* Summer: \b[$2.06^2=4.2436$].
* Fall: \b[$3.21^2=10.3041$].
No unit is printed in the held table, so a numerical concentration unit should not be invented. The markedly smaller summer <variance> is also a warning when assessing the common-variance assumption of ordinary <ANOVA>.