Question

1) the sum of 15 obsevations is 420 find the mean ..                                                                        2) find the arthemetic mean of 17,31,12,27,15,19,23

Answer 1

1) sum=420
 no of observations = 15
 $mean = \frac{total sum of observations}{no of observations}$
mean=420/15=28

2) sum of observations=144
 no of observations=7
 so AM=144/7=20.6

Answer 2

Mean=sum of observations/number of observations. Therefore ,420/15=28 Mean of 17,31,12,27,15,19,23/7=144/7=20.571 PLEASE MARK AS THE BEST!!!☆★