Six bags of rice weigh 18, 25, 11, 30, 22 and 40 kilograms. What is… Step by Step

Step by step

The question

Question: find the median of 18, 25, 11, 30, 22 and 40.

Median of 18, 25, 11, 30, 22, 40

The median is the middle number, once the numbers are in order.

median: the middle one, in order

There are four choices.

First we solve it, the normal way.

Then we pick.

1 Put them in order

First we put them in order, smallest first: 11, 18, 22, 25, 30 and 40.

11, 18, 22, 25, 30, 40

We still have 6 numbers.

None is lost.

6 numbers ✓

2 Find the middle

We cross out the smallest and the biggest, one pair at a time.

And the next pair.

Two numbers are left in the middle: 22 and 25.

The median is halfway between them.

Halfway: we add them and divide by 2.

median = 22 + 252

22 plus 25 is 47.

median = 472

47 divided by 2 is 23.5.

So the median is 23.5.

median = 23.5

3 Pick the choice

Our answer is median = 23.5.

That is choice A.

A) 23.5

4 Why not the others

B is 24.33.

Wrong: that is the mean.

B) 24.33 ✗ that is the mean

C is 29.

Wrong: that is the range.

C) 29 ✗ that is the range

D is 20.5.

Wrong: used the middle of the list as written: put the numbers in order first.

D) 20.5 ✗ used the middle of the list as written: put the numbers in order first

Let's look back.

First: put them in order.

Then: find the middle.

Then: pick the choice.

Last: why not the others.

Answer