orSE=AE×nEWhere,SE= sum of entities,nE = number of entities,AE = Average of entities.Now, according to the question,Sum of the first two numbers = 75 × 2 = 150,number = 115 (given)∴ Sum of the last two numbers = 555 – (150 + 115)= 555 – 265 = 290∴ Required average = 290/2 = 145Hence, the required average of the last two numbers is 145.AE=