A Random Sample of 160 Car Purchases Are Selected and Categorized

question 15

Multiple Choice

A random sample of 160 car purchases are selected and categorized by age. The results are listed below. Theage distribution of drivers for the given categories is 18% for the under 26 group, 39% for the 26 -45 group, 31%for the 45-65 group, and 12% for the group over 65. Calculate the chi-square test statistic ?2 to test the claimthat all ages have purchase rates proportional to their driving rates. Use ? = 0.05. $\begin{array}{l|cccc}\text { Age } & \text { Under 26 } & 26-45 & 46-65 & \text { Over } 65 \\\hline \text { Purchases } & 66 & 39 & 25 & 30\end{array}$

• A) 75.101
• B) 85.123
• C) 101.324
• D) 95.431

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Definitions:

Artesian Well

A well tapping a confined aquifer, where the water pressure is sufficient to bring the water to the surface without pumping.

Water Table

The level below which the ground is completely saturated with water, marking the boundary between the unsaturated soil and the groundwater.

Water Table

The upper surface of the saturated zone in the ground where the soil or rocks are permanently wet, marking the boundary between surface water and groundwater.

Topography

The arrangement of the natural and artificial physical features of an area.