Question

Consider the following frequency table:

Observation	Frequency
1	3
2	4
3	X
4	6

It is known that the total frequency is less than 20 and is divisible by 5. What is the value of X?

• A.
  1
• B.
  2
• C.
  6
• D.
  7

Answer 1

The correct option is B

2
The total frequency for the given table is 13 + X.
We know, frequency cannot be negative.
Therefore, the total frequency is greater than 13.
It is given that the total frequency is divisible by 5 and less than 20.
$\therefore$ the only number that satisfies this condition is 15.
(As the total frequency should also be greater than 13)

$\therefore$ 13 + X = 15
$\Rightarrow$ X = 2

Hence, 2 is the required answer.