Median and mean when there are 2 variables

[Natasha1]

Homework Statement

Here's a list of six numbers written in order of size

Relevant Equations

The numbers have



a median of 9

a mean of 11

Here's a list of six numbers written in order of size

4, 7, x, 10, y, y

The numbers have

a median of 9
a mean of 11

Find x and y?

So I've gone to do:

(4+7+x+10+2y)/2 = 11
I get
x+2y = 45

What do I need to do from here?

 

[PeroK]

What does a median of $9$ tell you?

I guess you meant:

(4+7+x+10+2y)/6 = 11

 

[Natasha1]

Oh yes, that's what I meant. Thank you PeroK :)

It means that

(x + 10)/2 = 9 right?

 

[Natasha1]

I get x = 8 and y = 18.5 is this correct?

 

[PeroK]

I get x = 8 and y = 18.5 is this correct?

Yes. You could have got $x = 8$ by looking at the median first.

 

[Mark44]

I get x = 8 and y = 18.5 is this correct?

If you substitute these numbers into the list do you get the stated mean and median? That's all you need to do to check.

 

[Natasha1]

no i don't

 

[Natasha1]

So what's y?

 

[PeroK]

no i don't

Why not?

 

[Natasha1]

2y = 37 which makes y = 18.5

Because if you add all of them you get (4 + 7 + 8 + 10 + 18.5 + 18.5)/6 = 11 doesn't work.

 

[Natasha1]

Oh yes it does!