The amount of sales tax paid on a purchase is rounded to the nearest cent. assume that the round-off error is uniformly distributed in the interval -.51 to .51 cents. (round the intermediate calculations to 4 decimal places. round your answers to 4 decimal places.) (a) write the formula for the probability curve describing the round-off error. f(x) = for ≤ x ≤ (c) what is the probability that the round-off error exceeds .4 cent or is less than -.4 cent