Chapter 17 Measures of Central Tendency Ex 17.5

Rajasthan Board RBSE Class 10 Maths Chapter 17 Measures of Central Tendency Ex 17.5

Question 1.
Astudent scored marks 46% in English, 67% ¡n Maths, 53% in Hindi, 72% in HLstory and 58% in Economics. As compared to other subject weightage given to Mathematics, then find weightage mean marks of student.
Solution :
As per question
x1 = 46, x2 = 67, x3 = 53, x4 = 72, x5 = 58
Let weightage of Hindi, History and Economics = x
Then weightage of Maths = 2x
and of English = 3x
So, here w1 = 3x, w2 = 2x, w3 = x, w4 = x, w5 = x,
Then, weightage arithmetic mean

Question 2.
Two candidates A and B scored following marks in different subject for entrance examination in Business School whose weightage are given alongwith:

By finding weightage mean find from A and B which is more capable?
Solution :

Mean weightage of A =  = 86.5
Again

Mean weightage of B =  = 87.25
∵ Weightage mean of A is less than that of B, so B is more capable.

Question 3.
Marks obtained by a student in Mathematics in three monthly tests are 85, 60 and 75 resp. And in annual exams begot 95 marks. Weightage of monthly tests are same where as weightage of annual exams is double that of monthly exams. Find the mean weightage of marks in Mathematics.
Solution :
According to question, x1 = 85, x2 = 60, x3 = 75, x4 = 95
and w1 = 1, w2 = 1, w3 = 1, w4 = 2,

Question 4.
There are 45 students is a class in which 15 are girls. Average weight of girls is 45 kg and of boys 52 kg. Find average weight of one student.
Solution :
According to question, average weight of 15 girls = 45 kg.
So, 
⇒ 45 = 
⇒ Σxi = 45 × 15 = 675
Total weight of 15 girls Σxi = 675 kg
Average weight of 30 boys = 52 kg

So, 
⇒ 52 = 
⇒ Σyi = 52 × 30 = 1560
Total weight of boys Σyi = 1560 kg
Average weight of 45 students
Σxi + Σyi = 675 + 1560 = 2235
Average weight of one student = 2235/45 = 49.67 kg.