A company accumulated the following data for a delivery truck

Miles Driven Total Cost

January 10,000 15,000

February 8,000 14,500

March 9,000 12,500

April 7,500 13,000

Required:

(a) Determine the equation to predict total cost for the delivery truck

(b) Calculate the total costs if 12,187 miles were driven

(c) Regression analysis is being used to find the line of best fit (Y=a+x) from eleven pairs of data. the calculations have produced the following information.

x =440, y=330, x=17,986, y=10,366, xy=13,467 and b=0.69171

what is the value of a in the equation for the line of best fit to two decimal places

(d) the correlation coefficient between advertising expenditure and sales revenue is calculated to be 0.85. which of the following statements is true. Show your workings.

a) 85% of the variations in sales revenue can be explained by the corresponding variation in advertising expenditure.

b) 72% of the variations in sales revenue can be explained by the corresponding variation in advertising expenditure.

c) Sales revenue will increase by 85% more than advertising expenditure will increase.

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