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## Class 10 (Foundation)

### Course: Class 10 (Foundation)>Unit 5

Lesson 2: Mean, median, mode

# Impact on median & mean: increasing an outlier

When a single high score in a group of four friends increases, the mean score also increases, but the median score stays the same. This is because the median is the middle number, which doesn't change, while the mean is the average of all scores, which does change.

## Want to join the conversation?

• I don't get the range, is it like average? Is it similar to the median? I'm really confused.
• The range is the max minus the min.
The average is the mean.

For example,
4, 3, 7, 9, 1, 5, 2
find the range and mean.

First, order the numerals in numerical order,
1, 2, 3, 4, 5, 7, 9
now first let's calculate the mean,
1+2+3+4+5+7+9 = 31
there are 7 numbers,
31 divided by 7 = 4.42857142857
now the range, easy.
what's 9 minus 1?
8.
range = 8
mean = 4.42857142857
(now that I think about it, this was a terrible example... it took like forever to calculate the mean...)
• For some reason I'm not seeing my comment in the comment section, so if it seems like I posted the same thing twice, I'm sorry.

I had a hard time understanding the wording with the first problem in this video because you didn't say "one number is literally 180, another is literally 220, and the 3rd number is somewhere in between those two." You said that the 3 other numbers (or high scores) are "[anywhere from] 180 to 220." Which means that they might not be 180 and 220; for example, the numbers could be 185, 192, and 216. So I think if you instead rewrote the problem like so: "Their scores are 180, 220, 250 and x" or something like that, learners would not have to guess what you are trying to say.
• First, how did you conclude two of the values are 220 and 180, can't it also be something like 210 and 190 ?
Second, The median of even number is the mean of the two middle, why the mean of the two middles ? can't it be just a number between them, or it is just a convention
• Probably the better way to state it would have been to say the 3 scores ranged from 180 to 220, ie 180, 220 and some unknown. Luckily, the actual values don't make any difference for this specific exercise. Only the change of the extreme value from 250 to 290 mattered.

Second, the statistical median determination in case of even number of data points is simply defined that way. I guess you could say were calculating the middle of the middle :)
• you ever eat bricks for fun i like the ones that have moss on them
• How can you take two of the numbers as 180 and 220 because the question only mentioned that the 3 scores were "between" 180 and 220?
• It's possible that the scores were just one less, which would make any calculations almost identical. Alongside that this question in particular isn't actually asking for any specific calculations, so it is easier to just use the numbers given rather than throwing more into the mix. This way you get the idea of what the distribution looks like.
• Are y’all in grade 5?
• yes i am in the 5th grade
• nope my a 6 grader
• What is outlier?