Question

Consider the following frequency table:

Observation	Frequency
5	6
10	12
15	X

It is known that the total frequency is not more than 20.
How many values of X are possible?

• A.
  4
• B.
  3
• C.
  2
• D.
  1

Answer 1

The correct option is B

3
The total frequency from the table is given by 6 + 12 + X = 18 + X
We know, 18 + X cannot be more than 20.

If we take X = 0, Total frequency is 18
If we take X =1, Total frequency is 18 + 1 = 19.
If we take X =2, Total frequency is 18 +2 = 20.

However if we take X =3, the total frequency becomes 18 +3 = 21, which is greater than 20.
Therefore, for any value of X that is greater than 2, our condition is not satisfied.
Hence, the possible values of X are 0,1,2
Therefore, 3 values of X are possible.