An investigator wants to test if there is a difference in endotoxin levels in children who are exposed to endotoxin (what type of variable is this?) as a function of their proximity to operating farms (categorized into 4 groups). The following are endotoxin levels in units per milligram of dust sampled from children's mattresses, organized by children's proximity to farms.

Select the most appropriate test statistic and run the appropriate test at a 5% level of significance. Calculate the appropriate test statistic (step 4 of the hypothesis testing). Round to 3 decimals