the mean of 15 observations was 25 . it was found later that an observation 40 was wrongly taken as 25 . the corrected new mean is
"explanation : correct sum = ( 25 * 15 + 40 - 25 ) = 390 correct mean = = 390 / 15 = 26 answer : e"
divide(add(multiply(25, 15), subtract(subtract(15, const_2), 25)), 15)