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4. A block of land with a building was acquired under contract on 12 June 1990 for $550 000 (including all incidental costs). The land and building were sold pursuant to a contract signed on 13 April 1999 for $750 000. The CPI index number for the quarter ending June 1990 is 57.1 and the CP index number for the quarter ending June 1999 is 68.1. Calculate the capital gain on disposal. Show your workings