there is not a significant difference in the percentage of returned parts between those who prefer using autoparts and those who prefer using the standard auto parts manual.there is not a difference in the percentage of returned parts between those who prefer using autoparts and those who prefer using the standard auto parts manual.there is not a significant relationship between the percentage of parts returned as to those who prefer autoparts and those who prefer using the standard parts manual.the percentage of returned parts does not match the overall percentage of returned parts of the population.