Question

On the board, your teacher shows an example of finding the range.

One of the numbers is erased, leaving what is shown.

Which of the following could NOT be true?
A: The missing number is 11
B: The missing number is 20
C: The missing number is 25
D: The missing number is 30

Answer 1

Answer:Median = Mid value of Set of observation

If number of observation is odd, suppose n

Median = th term

If number of observation is even , then

Median = Mean of two middle observation i.e

Data set : 17, 20, 30, 28, 18

Data arranged in ascending order: 17,18,20,28,30

Let one data =x

Number of observation is even.

Given, Median = 24

As , when number of observation is even , median is mean of two mid values.

Median=→→→ getting the median.

So, x must be greater than 30.

The correct option satisfying the above condition is Option (D) 34.

Explanation:

Answer 2

A. The missing number is 11

Explanation:

The highest number in the set is 30 and the lowest is 12, this makes the range 18.

30 is supposted to be there to make the range what the problem says it is: 12.

20 and 25 could be there because no matter what, as long as 30 is the greatest number, 20 and 25 don't effect the range AT ALL.

If 11 was in the number sequence, the lowest number would be 11, making the range 19, (30-11=19) which is not what the teacher is saying the range is.

So in short, A. The missing number is 11 is the correct answer.