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    We need slope = Sps/Sss. We know: R^2 = 0.4 = (Sps)/(Sss * Spp).

    We also have: Sss = (standard deviation of S)^2 = (4)^2 and Spp = (standard deviation of P)^2 = (8)^2.

    We need Sps = (deviation between S and P), which we must solve for.

    Solving for Sps from the R^2 equation above gives: Sps = (Sss * Spp) * R^2 = (4^2 * 8^2 * 0.4)

    Finally: Slope = Sps/Sss = (4^2 * 8^2 * 0.4)/(4^2) = 1.26. Which is the answer.