Q.1 Calculate arithmetic mean of the following data :

profit (in rs) : 0-10 10-2020-30 30-40 40-50 50-60

no of shops : 1218 27 20 17 16

Q.2. A candidate obtains 46% marks in english , 67% in mathematics , 50% in hindi 72% in history and 58% in economics . it is agreed to give triple weight to marks in english and double weight to marks in mathematics as compared to other subjects . calculate weighted mean . Also compare it with simple arithmetic mean .

Q.3. Calculate combined mean :

section mean marks no. of students

A 75 50

B 60 60

C 55 50

Ans. 2) Let the weight of other three subjects (i.e. Hindi, History and Economics) be 10. Therefore, weight for English is 30 (3×10) and weight for Mathematics (2×10).

Subject

Marks

(X)

Weight

(W)

WX

English

46

30

1380

Mathematics

67

20

1340

Hindi

50

10

500

History

72

10

720

Economics

58

10

580

 

 

ΣW = 80

ΣWX= 4520

Thus, the weighted mean of the marks is 56.5

 

Ans. 3)

Section

Mean Marks

Number of Students

(N)

A

B

C

 

Combined Arithmetic Mean

Thus, combined mean marks is 63.2

Due to paucity of time we providing solutions to only two of your question. Try solving the remain question yourself and in case of any difficulty do get back to us. 

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