Question

find the mean of the following data
xi 2 4 6 8
fi 5 10 16 7​

Answer 1

Step-by-step explanation:

xi fiCumulative frequency∣xi−M∣ fi∣xi−M∣ 5 8 8 216  7 6 14 0 0 9 2 16 2 4 10 2 18 3 612 220  5 10 15 6 26 8 48 Total 26   84Here, N=26 (even)

Median M=2(N/2)thobservation+(N/2+1)thobservation

M=213thobservation+14thobservation    

⇒M=27+7=7          (Here, 13 and 14 both lies in the cumulative frequency 14, so corresponding observation for both is 7)

Mean deviation about median =∑fi∑fi∣xi−M∣

=2684

=3.23