# Important Questions for CBSE Class 10 Maths Chapter 14 - Statistics 4 Mark Question

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CBSE Class 10 Maths Chapter-14 Statistics Important Questions

## 4 Mark Questions

1. In the following distribution, locate the median mean and mode.
 Monthly consumption of electricity 65-85 85-105 105-125 125-145 145-165 165-185 185-205 No. of consumers 4 5 13 20 14 7 4

Ans.

 Monthly consumption of electricity No. of consumers C.F Class Mark (X) FX 65-85 4 4 75 300 85-105 5 9 95 475 105-125 13 22 115 1495 125-145 20 42 135 2700 145-165 14 56 155 2670 165-185 8 64 175 1400 185-205 4 68 195 780 ∑ƒx=9320

Now and this is in 125-145 class
Median class = 125-145
Here,
We know that

Hence, Median = 137
Again Mean
For mode, since the maximum frequency is 20 and this corresponds to the class 125-145
Here,

Thus, Median = 137, Mean = 137.05 and Mode = 135.76
The three measures are approximately the same in the class.

1. Find the mean, mode and median for the following data:
 Classes 0-10 10-20 20-30 30-40 40-50 50-60 60-70 Frequency 5 8 15 20 14 8 5

Ans. We have

 Classes Mid-value Frequency C.f 0-10 5 5 -3 -15 5 10-20 15 8 -2 -16 13 20-30 25 15 -1 -15 28 30-40 35 20 0 0 48 40-50 45 14 1 14 62 50-60 55 8 2 16 70 60-70 65 5 3 15 75

Let assumed mean a = 35, h = length of class interval= 10
Mean

Since, Maximum frequency = 20
Modal class = 30-40

Mode =

Hence, mode = 34.55
Since,, which lies in the class 30-40
i.e., Median class = 30-40

Median =

Hence, Median = 34.75

1. Find the mean, mode and median for the following data:
 Classes 10-20 20-30 30-40 40-50 50-60 60-70 70-80 Frequency 4 8 10 12 10 4 2

Ans. We have

 Classes Mid value c.f 10-20 15 4 -3 -12 4 20-30 25 8 -2 -16 12 30-40 35 10 -1 -10 22 40-50 45 12 0 0 34 50-60 55 10 1 10 44 60-70 65 4 2 8 48 70-80 75 2 3 6 50

Let assumed mean a = 45, Here h = 10
We know that mean

Mean
Since maximum frequency = 12
Modal class = 40-50
Here,
Now Mode

Mode = 45
Now
Median class is 40-50
Now median
Here
Median =

Thus, Median = 42.5