Mathematics Multiple Choice Questions on “Statistics – Analysis of Frequency Distributions”.
1. An analysis of the monthly wages paid to the workers of a form is given below. Calculate the total monthly wages.
| No. of workers | 100 |
|---|---|
| Average monthly wages | 280 |
| Variance of distribution of wages | 10 |
a) 2800
b) 280
c) 28000
d) 2.8
Answer: c
Clarification: Number of wage earners (n1) = 100
Mean of monthly wages (X1) = ₹280
Mean of monthly wages = Total monthly wage/Number of workers
⇒ 280 = total monthly wages/100
⇒ Total monthly wages = 28000.
2. If the coefficient of variation is 100 the mean of the data is 25, then find the standard deviation.
a) 5
b) 10
c) 15
d) 25
Answer: d
Clarification: Coefficient of Variance = (Standard Deviation/Mean) × 100
⇒ Standard Deviation = 25.
3. If the standard deviation of a data is 820 and mean of the data is 50, find the coefficient of variation.
a) 16.4
b) 164
c) 1640
d) 1.64
Answer: a
Clarification: Coefficient of Variance = (Standard Deviation/Mean) × 100
⇒ Coefficient of Variance = (820/50) × 100 = 16.4.
4. If standard deviation of a data is 40 and the coefficient of variation is 25600, then find the mean.
a) 64
b) 6.4
c) 640
d) 0.64
Answer: b
Clarification: Coefficient of Variance = (Standard Deviation/Mean) × 100
⇒ Mean = 25600/4000 = 6.4.
5. The following data shows the heights and weights of the students of class 9. Which of the following is correct?
| Height | Weight | |
|---|---|---|
| Mean | 170 cm | 55 kg |
| Variance | 130 cm2 | 25 kg2 |
a) Coefficient of variation of weights > Coefficient of variation of heights
b) Coefficient of variation of weights < Coefficient of variation of heights
c) Coefficient of variation of weights = Coefficient of variation of heights
d) Coefficient of variation of weights = ½ Coefficient of variation of heights
Answer: a
Clarification: X̄1 = 170, X̄2 = 55, σ12 = 130 and σ22 = 25.
Now, Standard Deviation = √Variance
⇒ Standard deviation of height, σ12 = 130 ⇒ σ1 = √130 ⇒ σ1 = 11.40
and Standard deviation of weight, σ22 = 130 ⇒ σ2 = √25 ⇒ σ2 = 5
Also, Coefficient of Variance = (Standard Deviation/Mean) × 100
⇒ Coefficient of Variation in heights = (σ1/X̄1) x 100 = (11.40/170) x 100 = 6.7
and Coefficient of Variation in weights = (σ2/X̄2) x 100 = (5/55) x 100 = 9.09.
