💯 Maths

The mean height of 7 pupils is 123cm one pupil of height 147cm leaves the group find the mean of the 6 working out: 7x123=714 then divide that by 6 and then then answer is 119 cm?

1 answers
Mujavid BukhariSoftware Engineer, Ex-Googler and Computer Science at UCL17.5k students helped

7x123 = 861cm (total height) This is the total height of all 7 students. From this we must subtract the person of height 147cm. 861 - 147 = 714 cm Then divide by 6. 714 / 6 = 119cm So your answer was correct, but in your working out you made two small mistakes which cancelled out.