If r is the total resistance of three resistors, connected in parallel, with resistances r1, r2, r3, then 1 r = 1 r1 + 1 r2 + 1 r3 . if the resistances are measured in ohms as r1 = 64 ω, r2 = 20 ω, and r3 = 8 ω, with a possible error of 0.5% in each case, estimate the maximum error in the calculated value of r. (round your answer to three decimal places.)