Very Short Answer on Measures of Central Tendency Class 11 OP Malhotra Exe-20B ISC Maths Solutions Ch-20. In this article you would learn to solve hard questions on Measures of Central Tendency. Step by step solutions of latest textbook has been given as latest syllabus. Visit official Website CISCE for detail information about ISC Board Class-11.
Measures of Central Tendency Class 11 OP Malhotra Very Short Answer ISC Maths Solutions Ch-20
| Board | ICSE |
| Publications | S Chand |
| Subject | Maths |
| Class | 11th |
| Chapter-20 | Measures of Central Tendency |
| Writer | OP Malhotra |
| Exe-20(B) | Very Short Answer Type Questions. |
Very Short Answer on Measures of Central Tendency
OP Malhotra ISC Class 11 Maths Solutions
Que-1: Arithmetic mean of first 6 odd numbers is __________.
Sol: First 6 odd numbers: 1, 3, 5, 7, 9, 11
Sum = 36,
Mean = 36 / 6
= 6
Que-2: Mean of first ten whole numbers is __________.
Sol: Whole numbers: 0 to 9
Sum = 45,
Mean = 45 / 10
= 4.5
Que-3: The mean of first n natural numbers is __________.
Sol:
Mean = (n + 1) / 2
Que-4: The mean of the frequency distribution is:
| Marks obtained | 20 | 30 | 40 | 50 |
|---|---|---|---|---|
| No. of Students | 10 | 20 | 30 | 40 |
Sol: Mean = Σfx / Σf
= (20×10 + 30×20 + 40×30 + 50×40) / (10+20+30+40)
= (200 + 600 + 1200 + 2000) / 100
= 4000 / 100 = 40
Que-5: The mean of the frequency distribution is:
| Marks | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 |
|---|---|---|---|---|---|
| No. of Students | 6 | 12 | 18 | 10 | 4 |
Sol: Class marks: 15, 25, 35, 45, 55
Σfx = (15×6) + (25×12) + (35×18) + (45×10) + (55×4) = 1690
Σf = 50
Mean = 1690 / 50 = 33.8
Que-6: In the formula x̄ = A + (Σfᵢuᵢ / Σfᵢ) × h, what is uᵢ?
Sol: uᵢ = (xᵢ − A) / h
Que-7: The A.M. of 1, 3, 3², …, 3ⁿ⁻¹ is __________.
Sol: It is a GP: a = 1, r = 3
Sum = (3ⁿ − 1) / (3 − 1) = (3ⁿ − 1)/2
Mean = [(3ⁿ − 1)/2] / n
= (3ⁿ − 1)/(2n)
Que-8: The mean for the following frequency distribution is 12.58. Find x₁.
| xᵢ | 5 | 8 | 10 | 12 | x₁ | 20 | 25 |
|---|---|---|---|---|---|---|---|
| fᵢ | 2 | 5 | 8 | 22 | 7 | 4 | 2 |
Sol: Using Mean formula: x̄ = Σfx / Σf
12.58 × 50 = known terms + 7x₁
Solve to get: x₁ = 15
Que-9: Mean of 12 numbers is 26. If 5 is added to each number, find new mean.
Sol: Given mean = 26 and number of terms = 12
⇒ Total sum = 26 × 12 = 312
If 5 is added to each number, total increase = 5 × 12 = 60
New sum = 312 + 60 = 372
New mean = 372 ÷ 12 = 31
Que-10: A class has 50 students (30 girls). Mean marks: girls = 73, boys = 71. Find overall mean.
Sol: Total marks = (30×73) + (20×71)
= 2190 + 1420 = 3610
Mean = 3610 / 50 = 72.2
–: End Measures of Central Tendency Class 11 OP Malhotra Exe-20B ISC Maths Ch-20 Solutions :–
Return to :- OP Malhotra ISC Class-11 S Chand Publication Maths Solutions
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