Problem: the mean of 50 observations was 40 . it was found later that an observation 48 was wrongly taken as 23 . the corrected new mean is
Rationale: "sol . therefore correct sum = ( 40 × 50 + 48 – 23 ) = 2023 . therefore correct mean = 2023 / 50 = 40.46 . answer a"
annotated_formula: divide(add(multiply(40, 50), subtract(subtract(50, const_2), 23)), 50)