Explain the meaning of the following term:

Class mark

Explain the meaning of the following term:

Class limit

Explain the meaning of the following term:

True class limits

Explain the meaning of the following term:

Frequency of a class

Explain the meaning of the following term:

Cumulative frequency of a class.

The blood groups of$30$ students of a class are recorded as under:

$A, B, O, O, AB, O, A, O, A, B, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O$.

Represent this data in the form of a frequency distribution table.

The blood groups of$30$ students of a class more than its complement.

$A, B, O, O, AB, O, A, O, A, B, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O$

Find out which is the most common and which is the rarest blood group among these students.

Three coins are tossed $30$ times. Each time the number of heads occurring was noted down as follows:

$0, 1, 2, 2, 1, 2, 3, 1, 3, 0, 1, 3, 1, 1, 2, 2, 0, 1, 2, 1, 0, 3, 0, 2, 1, 1, 3, 2, 0, 2$

Prepare a frequency distribution table.

Following data gives the number of children in $40$ families:

$1 ,2, 6, 5, 1, 5, 1, 3, 2, 6, 2, 3, 4, 2, 0, 4, 4, 3, 2, 2, 0, 0, 1, 2, 2, 4, 3, 2, 1, 0, 5, 1, 2, 4, 3, 4, 1, 6, 2, 2$

Represent it in the form of a frequency distribution, taking classes $0-2, 2-4$ etc.