Mobile home construction in the state is doing very well. Figures from the Manufactured Housing Institute (MHI) for 1984 rank North Carolina third in the number of units manufactured with 28,197. Only Texas and Georgia produced more. Two of the four major third tier companies are located in the state - Oakwood and Conner. They soon may be joined by a third as Manufactured Homes, Inc. of Winston-Salem has announced its entry into the manufacturing side of the business.