The mean weight of a group of 15 students is 62.5kg. If a new student

1.	The mean weight of a group of 15 students is 62.5kg. If a new student is added and he weighs 75kg what is the new mean?
Answer» $\huge\boxed{\fcolorbox{purple}{ink}{Answer}}$ Original mean = 62.5 kg Original NUMBER of students = 15 students We KNOW that, ${\sf{Mean\: =\: {\dfrac{Sum\: of\: <klux>WEIGHT</klux>\: of\: students}{Total\: no\: of\: students}}}}$ ${\sf{\implies\: 62.5\: =\: {\dfrac{Sum\: of\: weight\: of\: students}{15}}}}$ ${\sf{\implies\: Sum\: of\: weight\: of\: students\: =\: 62.5\: \times\: 15}}$ = 937.5 kg New sum of weight = 937.5kg + 75kg = 1012.5 kg New no. of students = 15 + 1 = 16 ${\sf{New\:Mean\: =\: {\dfrac{New\:sum\: of\: weight}{New\:total\: no\: of\: students}}}}$ ${\sf{\implies\: New\:Mean\: =\: {\dfrac{1012.5}{16}}}}$ = 63.28 kg ${\bold{\boxed{\blue{New\: Mean\: =\: 63.28 kg}}}}$