A survey of households in a certain municipality is to be conducted to estimate the average annual expenditure on food. A pilot study has estimated the standard deviation of expenditures to be $825. What is the number of households required to estimate, with 80% confidence, the average annual expenditure on food with a margin of error not exceeding $150? According to the municipal census, the municipality currently has 1828 households. - 79 - 151 - 181 - 110 - 49