No. 8510PTC1359 Filed 19 August 1986 Taxation 25.4 — ad valorem taxes — public service company — inequitable difference in valuation By introducing a sales/assessment ratio study showing that Guilford County appraised locally assessed real property at 80.12% of true market value for 1983, a power company established a prima facie case of "inequitable difference" under N.C.G.S. 105-342 (c) between the level of assessment of locally appraised property in Guilford County and the level of the 1983 assessment