Numerical based on averages

Numerical based on averages

The mean of a certain number of items is 20.If an observation 25 is added to the data, the mean becomes 21.Find the number of items in the original data. (Sol:- 4)
The mean age of a combined group of men and women is 30 years. If the mean age of the men’s group is 32 years and that for the women’s group is 27 years, find the percentage of men and women in the combined group. (Sol: - 60%, 40%)
A distribution consists of three components each with total frequency of 200,250 and 300 and with means of 25, 10 and 15 respectively. Find out the mean of combined distribution
(Sol:-16)
Find GM from the following daily income of 10 families:-
85, 70,15,75,500,8,45,250,40 and 36 (Sol:-58.04)
5.) Calculate the weighted harmonic mean of the following data:
X: 3 10 25 40
W: 6 3 4 1 (Sol:-5.63)
Calculate quartiles ,D7 and P85 from the data
Class
Less than 100
100-250
250-400
400-500
500-550
550-600
600-800
800-900
900-1000
Frequency:
85
100
175
74
66
35
5
18
2
(Sol: - 182.5, 481.08, 443.24, 531.82)
Find the median from the following distribution:
X: 1 2 3 4 5-9 10-14 15-19 20-25
F: 5 10 16 20 30 15 8 6
(Sol: - 5.17)
The table gives the marks obtained by 70 students in mathematics. Calculate arithmetic mean and geometric means
Marks (more than): 80 70 60 50 40 30 20
No. of students: 0 7 18 40 40 63 70
(Sol: - 49, 46.39)
Locate mode of the following series:
X : 1 2 3 4 5 6 7 8 9 10 11 12
F : 9 7 4 9 10 8 4 10 5 8 15 8
(Sol: - 11)
An incomplete distribution is given below:
Variable:
0-10
10-20
20-30
30-40
40-50
50-60
60-70
F:
10
20
F1
40
F2
25
15
you are given that median value is 35, and N=170,find out missing frequencies
Calculate the Arithmetic mean and mod of completed data
(Sol: - f1=35, f2=25, AM= 35.88, Z=32.5)

Student of Rai Business School -New Delhi

Sanjeev Kumar SIngh