Question

I want a complete explanation with writing the laws and updating the table with values ​​f, fx, midpoint

أنماط فترة o, псор уоu са о коw с ромашку о паушу ташу сапіса ош иіс сошg aaay. 3) A sample of teenagers were and asked about the monthly hours each spent on social media, the results are shown in the below table. Using the information in the below table calculate the coefficient of variation (CV). Hours Number of students 10 to 14 15 to 19 20 to 24 25 to 29 30 to 34 35 to 39 40 to 44

Answer 1

Using MS-excel we find cv for this data

Class in	freq(fi)	midpoint(xi)	fixi	fi*xi^2
10 to 14	2	12	24	288
15 to 19	12	17	204	3468
20 to 24	23	22	506	11132
25 to 29	60	27	1620	43740
30 to 34	77	32	2464	78848
35 to 39	38	37	1406	52022
40 to 44	8	42	336	14112
	220	189	6560	203610

For coefficient of variation, we want to mean and standard deviation value so firstly we find this value for this data

1) Mean=$\sum fixi/\sum fi$

=6560/220

=29.8181

Mean=29.8181

2) variance=$\sum fi*x^2i- \left [ \left ( \sum fi*xi \right )^2/n \right ]/n-1$

=203610-(6560^2)/220/220-1

=8002.7272

36.5421

variance=36.5421

3) standard deviation=sqrt( variance)

=sqrt(36.5421)

S.D=6.0450

3) coefficient of variation:

C.V=S.D/mean*100

=0.2254*100

22.54

coefficient of variatin=22.54