Question

The blood groups of $30$students of Class VIII are recorded as follows:$A,B,O,O,AB,O,A,O,B,A,O,B,A,O,O,A,AB,O,A,A,O,O,AB,B,A,O,B,A,B,O.$

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

Which is the most common, and which is the rarest, blood group among these students?

Answer 1

frequency distribution : A frequency distribution is a representation, either in a graphical or tabular format, that displays the number of observations within a given interval.

It can be observed that $9$students have their blood group as$A$, $6$as $B$, $3$as$AB$, and$12$ as $O$

Therefore the blood group of $30$students of the class can be represented as follows:

Blood group	Tally marks	Frequency
$A$	$\cancel{\left|\right|\left|\right|}\left|\right|\left|\right|$	$9$
$B$	$\cancel{\left|\right|\left|\right|}|$	$6$
$AB$	$\left|\right||$	$3$
$O$	$\cancel{\left|\right|\left|\right|}\cancel{\left|\right|\left|\right|}\left|\right|$	$12$
Total		$30$

Hence, The frequency distribution table for the data is the above table.

From the observation of the above table,

The highest frequency is $12$which is for the blood group$O$ and the least frequency is $3$which is for the blood group $AB$

Hence,

The most common blood group (highest frequency blood group) is $O$

The rarest blood group (least frequency blood group) is .$AB$