An Oil Change Shop Claims That They Will Change Your

question 8

Essay

An oil change shop claims that they will change your oil in under 15 minutes. To test this claim, a consumer
advocacy group takes a simple random sample of 10 customers and records the number of minutes it took to
complete oil changes for these customers. Assume that oil change times are normally distributed. $$\begin{array} { | c | } \hline \text { Minutes for Oil Change } \\\hline 8 \\\hline 2 \\\hline 7 \\\hline 12 \\\hline 14 \\\hline 11 \\\hline 25 \\\hline 8 \\\hline 43 \\\hline 15 \\\hline\end{array}$$ Conduct a hypothesis test for the oil shop's claim about oil change times at the 5% level of significance.

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Definitions:

Consumer Surplus

The difference between what consumers are willing to pay for a good or service versus what they actually pay, measuring the benefit to consumers from market transactions.

Price Ceiling

A legal maximum price that can be charged for a product or service, intended to protect consumers from high prices.

Consumer Surplus

The discrepancy between what consumers are ready and capable of spending for a good or service, as shown by the demand curve, and the actual amount paid by them, known as the market price.

Producer Surplus

The difference between what producers are willing to accept for a good or service versus what they actually receive, due to market prices.