A Researcher Wanted to Determine If Using an Octane Booster

question 53

Multiple Choice

A researcher wanted to determine if using an octane booster would increase gasoline mileage. A random
sample of seven cars was selected; the cars were driven for two weeks without the booster and two weeks
with the booster.
$$\begin{array} { | l | l | } \hline \text { Miles / Gal Without } & \text { Miles / Gal With } \\\hline 21.2 & 23.8 \\\hline 25.4 & 25.6 \\\hline 20.9 & 22.4 \\\hline 27.6 & 28.3 \\\hline 22.8 & 24.5 \\\hline 27.3 & 28.8 \\\hline 23.4 & 25.2 \\\hline\end{array}$$
-Compute the standard deviation of the difference.

• A) 0.78
• B) 0.69
• C) 0.87
• D) 0.48

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Definitions:

Nasrids

The last Muslim dynasty in Spain, ruling the Emirate of Granada from the 13th to the 15th century until the Reconquista.

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Hypostyle Prayer Hall

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Horseshoe-Shaped Arches

Architectural elements that resemble a horseshoe, wider than they are tall, often used in Islamic and Moorish architecture.