of Take me to the text Jess Brady sells gifts certificates for $75 each. She purchases each gift certificate for $13 and spends $4,800 for fixed costs. Do not enter dollar signs or commas in the input boxes. Round your answers to the nearest whole number. a) Calculate operating income if Jess sells 470 gift certificates Operating Profit: $ b) Calculate the revenues needed to obtain an operating income of $4,900. Required Revenue: $ Check Contact us!