Class interval

Q.

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

1. Evenly distributed over all the classes

2. Centred at the class marks of the classes

3. Centred at the upper limits of the classes

4. Centred at the lower limits of the classes

Q.

If each observation is increased by 5, then its mean _____

1. 18

2. 68

3. 45

4. 80

Q.

What do you call the value that is halfway between the upper and lower limits of a class interval?

__

Q. In a frequency distribution, mid-point of a class is 10 and class width is 6. The lower limit of the class is:

1. 6
2. 12
3. 8
4. 7

Q.

For calculating mean of grouped data, the mid point of each class interval is chosen to represent all the observations from that class.

1. True

2. False