On the board your teacher writes 17,20,30,28,18 of how to find the median. One of the numbers is erased leaving what is shown which choice could be true A 12 B 22 C24 D34

None, since the numbers you have given, the median is 20

I think you are missing a number or made a mistake

You can find a median by first ordering the numbers

Then, you try to find the middle number.

For example:

3, 5, 7, 12, 13, 14, 21, 23, 23, 23, 23, 29, 39, 40, 56

Since there are odd amount of numbers, it is easy to find the middle number.

Since there are 15 numbers, the 8th one will be the median which is 23

But, if there are even amount of numbers such as like this:

3, 5, 7, 12, 13, 14, 21, 23, 23, 23, 23, 29, 40, 56

There are 16 numbers and the middle ones are 21 and 23.

Simple, you have to add 21 and 23 which you get 44 and then divided by 2

44/2=22

The median for that problem is 22

Now, try to find the correct numbers to find the correct numbers to find the correct median