Hexavalent chromium has been identified as an inhalation carcinogen and an air t
ID: 3376160 • Letter: H
Question
Hexavalent chromium has been identified as an inhalation carcinogen and an air toxin that causes concern in some geographical locations The accompanying table gives some summary data about the indoor and outdoor concentrations (in nanograms per cubic meter) of hexavalent chromium for one random sample of 33 houses from a large metropolitan area. We want to know if the data provide evidence of a significant difference in hexavalent chromium levels indoor and outdoor Which inference procedure should be used? (1 point) Statisti Mean Standard Error Median Standard Deviation Variance Minimum Maximum Sum Count Indoor Outdoor Difference(Out-In 0.406 0.068 0.31 0.392 0.154 -0.26 1.39 13.4 0.231 0.022 0.19 0.128 0.016 0.07 0.62 7.62 0.637 0.068 0.52 0.392 0.154 0.09 1.59 21.02 O A: one sample or matched-pairs t procedure for a mean B: two sample t procedure for two means C: ANOVA for several means D: z procedure for a proportion E: chi-square for two-way tablesExplanation / Answer
as here sample is same for both observations therefore samples are dependent
option A is correct ; one sample or matched pair t procedure for a mean