Question

The following excerpt is from an article "State reports find fraud rate of 42% in auto body repairs," published in the Sacramento Bee newspaper in September of 2003. The Bureau of Automotive Repair (BAR), a branch of the California Department of Consumer Affairs, investigates complaints about collision-repair shops in California. "For the past two years, ... consumers have been steered to BAR to determine if their cars had been properly fixed by collision-repair shops across the state. Of the 1,315 vehicles inspected in the two year BAR study that ended in June, 42 percent were overbilled for labor not performed or parts not supplied, Consumer Affairs Director Kathleen Hamilton said at a news conference last week.... the average loss was $812." Determine if the following two critiques of the BAR study are valid or invalid: The article continues, "Officials in the auto-body repair industry blasted the report. 'This is not a true random inspection but a complaint-driven inspection,' said David McClune, chief of the California Autobody Association. The cars belong to disgruntled drivers, he claimed. 'The results of this study can't be projected upon the industry as whole,' said McClune."
(i) Valid
(ii) Invalid

Answer 1

Answer:

i) valid

Explanation:

The research only included car owners (and their cars) that suspected that auto repair shops had not done their job properly. The 42% of fraud rate is applicable to that specific population which is car owners that suspect auto repair shops have committed fraud. It is not representative of the general population of all the car owners whose cars have been repaired.

It is like making a research in a university campus and saying that 99% of the US population buys college books. Maybe 99% (or even 100%) of all college students buy college books, but the rest of the population doesn't and they do not have a reason to do so either.