the file p02 35.xlsx contains data from a survey of 500 randomly selected households. for this problem, consider this data set a simple random sample from all possible households, where the number of households in the population is well over 1,000,000. create a new variable, total income, that is the sum of first income and second income. a. for each of the four variables total income, monthly payment, utilities, and debt, find the sample mean. round your answer to the nearest whole dollar, if necessary.