Find the class interval with lowest frequency.

Class Limits	Class Boundaries	Tally	Frequency
$318 - 335$	$317.5 - 335.5$	$||||$	$4$
$336 - 353$	$335.5 - 353.5$	$||||$	$5$
$354 - 371$	$353.5 - 371.5$	$||$	$2$
$372 - 389$	$371.5 - 389.5$	$|||$	$3$
$390 - 407$	$389.5 - 407.5$	$|||$	$3$
$408 - 425$	$407.5 - 425.5$	$||$	$2$
$426 - 443$	$425.5 - 443.5$	$|$	$1$

A) $318 - 335$
B) $354 - 371$
C) $372 - 389$
D) $426 - 443$

Hint: In the given table we have different class intervals and its respective frequencies. First, we need to analyse the given data, that is, we need to write down the frequency of each class interval and from that we need to compare the frequencies to find out which class interval has the least frequency.

Complete step-by-step answer:
We are given a table with class intervals and its frequencies.
Now let’s see the frequency of each class interval.
The first interval $318 - 335$ has a frequency of $4$ .
The interval $336 - 353$ has a frequency $5$
The interval $354 - 371$ has a frequency $2$
The interval $372 - 389$ has a frequency $3$
The interval $390 - 407$ has a frequency $3$
The interval $408 - 425$ has a frequency $2$
The interval $426 - 443$ has a frequency $1$
From the given data we can see that the class interval $426 - 443$ has the least frequency, that is $1$ .
Let’s discuss the given options
The first option is $318 - 335$ and from the given data we can see that its frequency is $4$ . But we can see that their frequencies are less than that in other class intervals. So, this option is not correct
The second option is $354 - 371$ and from the given data we can see that its frequency is $2$ . But we can see that their frequencies are less than that in other class intervals. So, this option is not correct
The first option is $372 - 389$ and from the given data we can see that its frequency is $3$ . But we can see that their frequencies are less than that in other class intervals. So, this option is not correct
The first option is $426 - 443$ and from the given data we can see that its frequency is $1$ . We can see that there are no other frequencies less than that in other class intervals. So, it is the correct option

So, the correct answer is “Option D”.

Note: Students need to analyse each and every class interval for their respective frequencies to compare which is smaller and which is greater. Many tend to mismatch the class intervals with the different frequencies which may end in errors. In the class interval $336 - 353$ , the frequency is $5$ but many students tend to take the strikethrough symbol in the wrong way and assume that frequency to be $0$ .