Regular and Irregular Class Interval

Q.

The steps to convert an irregular class interval into a regular one, are

Step 1: Compute correction factor which is $\frac{\text{upper class limit-lower class limit of previous class interval}}{2}$.

Step 2: This is added to the upper limit and subtracted from the lower limit of each class.

1. Step 1 is correct, but step 2 is incorrect.

2. Step 1 is incorrect, but step 2 is correct.

3. Both steps are correct

4. Both steps are incorrect.

Q.

Draw a cumalitive frequency curve (ogive) for each of the following distributions :

(i) $\begin{array}{ccccccc}Classinterval& 10-15& 15-20& 20-25& 25-30& 30-35& 35-40\\ Frequency& 10& 15& 17& 12& 10& 8\end{array}$

(ii) $\begin{array}{cccccc}Classinterval& 10-19& 20-29& 30-39& 40-49& 50-59\\ Frequency& 23& 16& 15& 20& 12\end{array}$
$\left[4Marks\right]$

Q.

Assertion: We find midpoints of a class interval with the following formula.
$\frac{upperclasslimit+lowerclasslimit}{2}$
Reason: To draw frequency polygons independently without drawing histogram it is required to have the class mark.
Which of the following is correct?

1. A is true and R is false

2. Both A and R are true and R is the correct explanation of A

3. A is false and R is true

4. Both A and R are true but R is not the correct explanation of A