Van Mahotsava was celebrated in $100$ schools,where $100$ plants were planted in each school. After one month,the number of plants that survived were recorded as follows:
$\begin{array}{llllllllll}95 & 67 & 28 & 32 & 65 & 65 & 69 & 33 & 98 & 96 \\ 76 & 42 & 32 & 38 & 42 & 40 & 40 & 69 & 95 & 92 \\ 75 & 83 & 76 & 83 & 85 & 62 & 37 & 65 & 63 & 42 \\ 89 & 65 & 73 & 81 & 49 & 52 & 64 & 76 & 83 & 92 \\ 93 & 68 & 52 & 79 & 81 & 83 & 59 & 82 & 75 & 82 \\ 86 & 90 & 44 & 62 & 31 & 36 & 38 & 42 & 39 & 83 \\ 87 & 56 & 58 & 23 & 35 & 76 & 83 & 85 & 30 & 68 \\ 69 & 83 & 86 & 43 & 45 & 39 & 83 & 75 & 66 & 83 \\ 92 & 75 & 89 & 66 & 91 & 27 & 88 & 89 & 93 & 42 \\ 53 & 69 & 90 & 55 & 66 & 49 & 52 & 83 & 34 & 36\end{array}$

(N/A) To present such a large amount of data so that a reader can make sense of it easily,we condense it into groups like $20-29, 30-39, . . ., 90-99$ (since our data ranges from $23$ to $98$). These groupings are called 'classes' or 'class-intervals',and their size is called the class-size or class width,which is $10$ in this case. In each of these classes,the least number is called the 'lower class limit' and the greatest number is called the 'upper class limit'. For example,in $20-29$,$20$ is the lower class limit and $29$ is the upper class limit.
Using tally marks,the data above can be condensed into a grouped frequency distribution table as follows:

Number of plants survived	Number of schools (frequency)
$20-29$	$3$
$30-39$	$14$
$40-49$	$12$
$50-59$	$8$
$60-69$	$18$
$70-79$	$10$
$80-89$	$23$
$90-99$	$12$
Total	$100$

Presenting data in this form simplifies and condenses it,enabling us to observe important features at a glance. We can observe that $50\%$ or more plants survived in $8 + 18 + 10 + 23 + 12 = 71$ schools.