# While computing mean of grouped data, we assume that the frequencies are

a. evenly distributed over all the classes

b. centred at the classmarks of the classes

c. centred at the upper limits of the classes

d. centred at the lower limits of the classes

**Solution:**

While computing mean of grouped data, we assume that the frequencies are centred at the classmarks of the classes

Therefore, the frequencies are centred at the classmarks of the classes.

**✦ Try This: **Write the formula to find mean for grouped data direct method.

Mean x = Σf_{i}u_{i}/Σf_{i}

Where

fi is the frequency for that particular class

ui is the mid point of that particular class

Therefore, the formula to find the mean is \(\overline{x}\) = Σf_{i}u_{i}/Σf_{i}.

**☛ Also Check: **NCERT Solutions for Class 10 Maths Chapter 14

**NCERT Exemplar Class 10 Maths Exercise 13.1 ****Problem 2**

## While computing mean of grouped data, we assume that the frequencies are a. evenly distributed over all the classes, b. centred at the classmarks of the classes, c. centred at the upper limits of the classes, d. centred at the lower limits of the classes

**Summary:**

While computing the mean of grouped data, we assume that the frequencies are centred at the classmarks of the classes

**☛ Related Questions:**

- If xi ’s are the mid points of the class intervals of grouped data, fi ’s are the corresponding freq . . . .
- In the formula x̄ = a + h fi ui/ fi, for finding the mean of grouped frequency distribution, ui = a. . . . .
- The abscissa of the point of intersection of the less than type and of the more than type cumulative . . . .

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