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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Definitions:

Cash Sales

Transactions where goods or services are paid for with cash at the time of the sale.

Sales Discount

is a reduction in the listed price of a product or service offered to customers as an incentive to prompt payment.

Sales Discount

A reduction in the price of goods or services offered by the seller to the buyer as an incentive for early payment.

Charge Customer

The act of billing a customer for goods or services provided, usually resulting in an accounts receivable entry for the business.