What are the required conditions for error variable in multiple regression analysis? The Internal Revenue Service (IRS) is trying to estimate the monthly amount of unpaid taxes discovered by its auditing division. The IRS estimated this figure on the basis of field auditing labor hours and number of hours of its computers used. The table given below presents these data for the last ten months.

Month	(X1) Field Audit Labor Hours in 100	(X2) Computer Hours in 100	(Y) Actual Unpaid Taxes Discovered million of dollars
Jan	45	16	29
Feb	42	14	24
Mar	44	15	27
April	45	13	25
May	43	13	26
June	46	14	28
Jul	44	16	30
Aug	45	16	28
Sep	44	15	28
Oct	43	15	27

Given ∑YX₁=12005, ∑YX₂=4013, ∑X₁X₂=6485, ∑Y²=7428, ∑X₁²=19461, ∑X₂²=2173

i. Develop the estimating equation best describing these data.

ii. Interpret the value of regression coefficients.

iii. Estimate the actual unpaid tax for field if audit labour hours is 4200 and computer hours is 1600 hours.