Median and mean when there are 2 variables

The median is the middle number when the numbers are in order. In this case, it's the average of x and 10. So the median is (x + 10)/2. And we know that this is equal to 9. So x + 10 = 18 and x = 8. And since the mean is 11, we know that (4 + 7 + 8 + 10 + 18.5 + 18.5)/6 = 11, which means that 2y = 37 and y = 18.5. In summary, the numbers x = 8 and y = 18.5 make the list (4, 7, 8, 10,
  • #1
Natasha1
493
9
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?
 
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  • #2
What does a median of ##9## tell you?

I guess you meant:

(4+7+x+10+2y)/6 = 11
 
  • #3
Oh yes, that's what I meant. Thank you PeroK :)

It means that

(x + 10)/2 = 9 right?
 
  • #4
I get x = 8 and y = 18.5 is this correct?
 
  • #5
Natasha1 said:
I get x = 8 and y = 18.5 is this correct?
Yes. You could have got ##x = 8## by looking at the median first.
 
  • #6
Natasha1 said:
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.
 
  • #7
no i don't
 
  • #8
So what's y?
 
  • #9
Natasha1 said:
no i don't
Why not?
 
  • #10
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.
 
  • #11
Oh yes it does!
 
  • Wow
Likes PeroK

Related to Median and mean when there are 2 variables

1. What is the difference between median and mean when there are 2 variables?

The median and mean are both measures of central tendency, but they differ in how they are calculated. The median is the middle value in a set of data when it is arranged in ascending or descending order. The mean is the average of all the values in a set of data. When there are 2 variables, the median and mean can be calculated for each variable separately or for the combined data set.

2. How do you calculate the median when there are 2 variables?

To calculate the median when there are 2 variables, you first need to arrange the data in ascending or descending order. Then, if there is an odd number of values, the median will be the middle value. If there is an even number of values, the median will be the average of the two middle values.

3. How do you calculate the mean when there are 2 variables?

To calculate the mean when there are 2 variables, you first need to find the sum of all the values for each variable separately. Then, divide each sum by the total number of values for that variable. Finally, add the two means together to get the mean for the combined data set.

4. What does the median represent in a data set with 2 variables?

The median represents the middle value in a data set when it is arranged in ascending or descending order. This can be useful when there are extreme values or outliers in the data, as it is not affected by these values. In a data set with 2 variables, the median can be used to compare the central values of each variable.

5. When is it more appropriate to use the mean instead of the median in a data set with 2 variables?

The mean is more appropriate to use when the data is normally distributed, meaning that the majority of values are clustered around the center. This is because the mean takes into account all the values in the data set, making it more sensitive to extreme values. In a data set with 2 variables, the mean can be used to compare the overall average of each variable.

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