Assume the average selling price for houses in a certain county is $295 comma 000 with a standard deviation of $56 comma 000. a) Determine the coefficient of variation. b) Caculate the z-score for a house that sells for $283 comma 000. c) Using the Empirical Rule, determine the range of prices that includes 95% of the homes around the mean. d) Using Chebychev's Theorem, determine the range of prices that includes at least 90% of the homes around the mean. a) Determine the coefficient of variation. CVequals 18.99% (Round to one decimal place as needed.) b) Calculate the z-score for a house that sells for $283 comma 000. zequals negative 0.21 (Round to two decimal places as needed.) c) Using the Empirical Rule, determine the range of prices that includes 95% of the homes around the mean. upper bound x equals $ nothing lower bound x equals $ nothing (Round to the nearest dollar as needed.) d) Using Chebychev's Theorem, determine the range of prices that includes at least 90% of the homes around the mean. upper bound x equals $ nothing lower bound x equals $ nothing (Round to the nearest dollar as needed.)