Prior to July 15th, the county legislative authority shall form a board for the equalization of the assessment of the property of the county. The members of said board shall receive a per diem amount as set by the county legislative authority for each day of actual attendance of the meeting of the board of equalization to be paid out of the current expense fund of the county: PROVIDED, That when the county legislative authority constitute the board they shall only receive their compensation as members of the county legislative authority. The board of equalization shall meet in open session for this purpose annually on the 15th day of July and, having each taken an oath fairly and impartially to perform their duties as members of such board, they shall examine and compare the returns of the assessment of the property of the county and proceed to equalize the same, so that each tract or lot of real property and each article or class of personal property shall be entered on the assessment list at its true and fair value, according to the measure of value used by the county assessor in such assessment year, which is presumed to be correct under RCW 84.40.0301, and subject to the following rules:

     First. They shall raise the valuation of each tract or lot or item of real property which is returned below its true and fair value to such price or sum as to be the true and fair value thereof, after at least five days' notice shall have been given in writing to the owner or agent.

     Second. They shall reduce the valuation of each tract or lot or item which is returned above its true and fair value to such price or sum as to be the true and fair value thereof.

     Third. They shall raise the valuation of each class of personal property which is returned below its true and fair value to such price or sum as to be the true and fair value thereof, and they shall raise the aggregate value of the personal property of each individual whenever the aggregate value is less than the true valuation of the taxable personal property possessed by such individual, to such sum or amount as to be the true value thereof, after at least five days' notice shall have been given in writing to the owner or agent thereof.

     Fourth. They shall reduce the valuation of each class of personal property enumerated on the detail and assessment list of the current year, which is returned above its true and fair value, to such price or sum as to be the true and fair value thereof; and they shall reduce the aggregate valuation of the personal property of such individual who has been assessed at too large a sum to such sum or amount as was the true and fair value of the personal property.

     Fifth. The board may review all claims for either real or personal property tax exemption as determined by the county assessor, and shall consider any taxpayer appeals from the decision of the assessor thereon to determine (1) if the taxpayer is entitled to an exemption, and (2) if so, the amount thereof.

     The clerk of the board shall keep an accurate journal or record of the proceedings and orders of said board showing the facts and evidence upon which their action is based, and the said record shall be published the same as other proceedings of county legislative authority, and shall make a true record of the changes of the descriptions and assessed values ordered by the county board of equalization. The assessor shall correct the real and personal assessment rolls in accordance with the changes made by the said county board of equalization, and the assessor shall make duplicate abstracts of such corrected values, one copy of which shall be retained in the office, and one copy forwarded to the department of revenue on or before the eighteenth day of August next following the meeting of the county board of equalization.

     The county board of equalization shall meet on the 15th day of July and may continue in session and adjourn from time to time during a period not to exceed four weeks, but shall remain in session not less than three days: PROVIDED, That the county board of equalization with the approval of the county legislative authority may convene at any time when petitions filed exceed twenty-five, or ten percent of the number of appeals filed in the preceding year, whichever is greater.

     No taxes, except special taxes, shall be extended upon the tax rolls until the property valuations are equalized by the department of revenue for the purpose of raising the state revenue.

     County legislative authorities as such shall at no time have any authority to change the valuation of the property of any person or to release or commute in whole or in part the taxes due on the property of any person.