Calculate the specificity of the screening test:\r\n \r\n \r\n\r\n\r\n\r\nScreening test results\r\n\r\n\r\nDiseased\r\n\r\nNot diseased\r\nTotal\r\n\r\n\r\n\r\nPositive\r\n\r\n\r\n400\r\n\r\n\r\n200\r\n\r\n\r\n600\r\n\r\n\r\n\r\n\r\nNegative\r\n\r\n\r\n100\r\n\r\n\r\n600\r\n\r\n\r\n700\r\n\r\n\r\n\r\n\r\nTotal\r\n\r\n\r\n500\r\n\r\n\r\n800\r\n\r\n\r\n1300\r\n\r\n\r\n\r\n