Question

A cricketer has mean score of 58 run in 9 innings .Find out how many runs are to be scored in the 10th inning to raise the mean score to 61

Answer 1

mean score of 9 innings is 58 
total  runs in 9 innings = 58*9
                                    = 522
runs should scored in 10th innings to mean score 61 be X

61=522+X/10
610=522+X
X= 88

Answer 2

we know that mean = ∑N/ n = sum of observations/ no.of observations
given.
mean runs in 9 innings = 58
let, the sum of all runs in 9 innings = x
⇒ x/ 9 =58
⇒x = 58×9 = 522
 let,the no.of runs that should be taken in the 10th inning =y
⇒(522 + y)/ 10 = 61
⇒522 + y = 610
⇒y = 610 - 522
⇒y = 88
the no.of runs that should be scored in 10th inning to get a mean score of 61 = 88 runs