A study of the influence of corrosion inhibitor on the failure of aluminum-wired twist-on connections, the data obtained with one sample of connectors wired with alloy aluminum and another sample wired with EC aluminum are:
Alloy 20 size 17.5 mean 0.55 stand dev
EC 20 size 16.9 mean 0.49 Stand dev
Does this data suggest that true average potential drop for alloy conenctions are higher than for EC connections? Carry out apropriate test using a significance level of 0.01.