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In a market model, quantity demanded is a function of price: q = f(p). An economist suspects a linear relationship between quantity demanded and price. In four different weeks she observes the price in euros per unit and the number of units sold. The results are summarised in the following table: Price p Quantity demanded q 10 50 14 44 18 36 22 30 a. Find the sample standard deviations of p and q. Round your answer to the second decimal. b. Find the sample covariance and the coefficient of correlation of p and q. Round your answers to the second decimal. C. Find the equation of the linear regression line of q on p, according to the method of least squares. d. Give an estimation of the quantity demanded if the price is set as p = 15. Round your answer to the nearest integer