A Local Consumer Reporter Wants to Compare the Average Costs

Multiple Choice

A local consumer reporter wants to compare the average costs of grocery items purchased at three different supermarkets, A, B, and C. Prices (in dollars) were recorded for a sample of 60 randomly selected grocery items at each of the three supermarkets. In order to reduce item-to-item variation,
The prices were recorded for each item on the same day at each supermarket.
The results of a Bonferroni analysis are summarized below. $$\begin{array} { l c c c } \text { Supermarket } &\mathrm { A } & \overline{\mathrm { B }\quad\quad\quad \quad \mathrm { C }} \\\text { Mean Price } & 1.665 & 1.919 \quad1.925\end{array}$$ Interpret the Bonferroni analysis results.

A) A has a significantly smaller mean price than either of the other two supermarkets.
B) C has a significantly larger mean price than either of the other two supermarkets.
C) B and C have significantly different mean prices.
D) A has a significantly larger mean price than either of the other two supermarkets.