(Solved): A consumer advocate researches the length of life between two brands of refrigerators, Brand A and ...
A consumer advocate researches the length of life between two brands of refrigerators, Brand A and Brand B. He collects data (measured in years) on the longevity of 40 refrigerators for Brand A and repeats the sampling for Brand B. A portion of the data is shown in the accompanying table. (You may find it useful to reference the appropriate table: ztable or ttable) Click here for the Excel Data File Assume that ?1? is the mean longevity for Brand A and ?2? is the mean longevity for Brand B. a. Select the competing hypotheses to test whether the average length of life differs between the two brands. H0?:?1???2?=0;HA?:?1???2??0H0?:?1???2??0;HA?:?1???2?<0H0?:?1???2??0;HA?:?1???2?>0? b-1. Calculate the value of the test statistic. Assume that ?A2=4.8 and ??2=6,4. (Negative value should be indicated by a minus sign. Round final answer to 2 decimal places.)