Annual income per capita in hundreds of dollars (X₁), number of houses listed for sale in the market (X₂) and unemployment rate (X₃) in a region have been selected to help predict average number of houses sold per month. The estimated least squares regression equation was computed to be: Y = 7 830 + 22.8 X1 + 0.77 X2 - 3500 X3 Predict the mean number of houses sold per month for a region with annual per capita income of $56800, an unemployment rate of 6%, and 300 houses listed on the market. Leave one decimal place.