A Local Tire Dealer Wants to Predict the Number of Tires

question 18

Short Answer

A local tire dealer wants to predict the number of tires sold each month. He believes that the number of tires sold is a linear function of the amount of money invested in advertising. He randomly selects 6 months of data consisting of tire sales (in thousands of tires) and advertising expenditures (in thousands of dollars). Based on the data set with 6 observations, the simple linear regression model yielded the following results.
∑X = 24
∑X² = 124
∑Y = 42
∑Y² = 338
∑XY = 196
Calculate the sample correlation coefficient.

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United States

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Fraction

A mathematical expression representing the division of one quantity by another, indicating parts of a whole or a ratio.

Ozone Layer

A layer in the earth's stratosphere containing a high concentration of ozone, which absorbs most of the sun's ultraviolet radiation.

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Water molecules in the solid state that manifest in symmetrical patterns, typically forming under low temperature conditions in the atmosphere or on surfaces.