Question

Consider the following data:
$
  15,17,17,20,15,18,16,25,16,15,16,18,20,28,30, \\
  27,18,18,20,25,16,16,20,28,15,18,20,20,20,25
 $
Form a frequency table from the above data.

Answer 1

Hint: In this question, we are given certain observations and we have been asked to make a frequency table. For this, make a table involving three columns and name them- observations, tally marks, frequency. Write the given numbers under the heading observations in each row. Make a tally whenever the number appears in the given observations and at the end, write the corresponding frequency.

Complete step-by-step solution:
We are given certain observations and we have been asked to make a frequency table. Before moving towards the solution, let us know what the frequency table is.
What is a frequency table?
Frequency refers to the number of times a value appears. A frequency table is a list of items that occur in the observations and includes the frequency (the number showing how many times the same number appears). It includes three columns – the observation, frequency of observation and its tally marks.
We are given the following observations:
$
  15,17,17,20,15,18,16,25,16,15,16,18,20,28,30, \\
  27,18,18,20,25,16,16,20,28,15,18,20,20,20,25
 $
These numbers can be arranged into the table in the following way:

Observation	Frequency $(f)$
$15$	$4$
$16$	$5$
$17$	$2$
$18$	$5$
$20$	$7$
$25$	$3$
$27$	$1$
$28$	$2$
$30$	$1$

This is our final frequency table.

Note: Tally marks are a type of numbers, specifically used for counting. These are usually in a bunch of five. With an increase in one number, one tally mark is drawn. The first four tally marks are drawn vertically and then the fifth line is drawn diagonally, striking the previous four tally marks, starting from the top left and ending at bottom right. For 6th observation, a new group of tally marks is started and this goes on and on. Usually, the tally mark used to strike the four previous tally marks is slanting (\).