How to Determine the Mean When Only Given the Box & Whisker Plots

Box and Whisker plot is a visual representation of a group of numbers. Expert Rachel Kaplove demonstrates how this method helps.

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[leonardovaldivia]

How to fail your math test:


1. Watch this video.
2. Do exactly what it says.


A box plot does not display mean/average.
So you just cant' get a mean from the graph because it does not have it.

[kylemcwhorter]

So if I only have a box & whisker plot, I just make up data points and get whatever mean I want?

[biglovehaha]

she is wrong...you cannot certainly find mean from box graph...please ignore this video

[carlosmanuelherreracastillo]

Video should be renamed just "How to Determine the Mean When Only Given the Box & Whisker Plots when sample size is 5". The box and whisker plot was not used alone, unless she's assuming that you have the previous knowledge that your data set consists of only 5 values. Only in that case, the first whisker (sample minimum) would correspond to the first value, the first side of the box (lower quartile) would correspond to the second value, the central line (median) would correspond to the third value, the last side of the box (upper quartile) would correspond to the fourth value and the last whisker (sample maximum) would correspond to the fifth value. Only then you could see a box and whisker plot, deduce the sample values and calculate the mean. But this method ONLY works consistently when the sample size is 5. It cannot be generalised to any other circumstance. Therefore, the title is misleading.

[aakashPotter]

This is incorrect. You cannot get the mean just from a 5 point summary of the data that is provided by the box & whisker plot. You need the entire dataset. Mean can be very different from the median due to outliers.

[TheDainerss]

On a scale of 10 being extremely helpful and 1 being not helpful at all, this video gets a -10.

[eileenweisz]

But this only goes for normal distributions right? Other wise you can't say it by using a box plot, or am I wrong?

[choebbel]

you could ONLY get the mean from the box plot if EVERY SINGLE data point was listed individually across the plot, which isn't really the point of a box plot. oh well, it was a sweet video.

[susaneileen]

very helpful video but.. how is she so good at writing backwards???

[danielbarrera]

This only works when the data is distributed evenly; otherwise, it is not true.

[huiyenlo]

Incorrect. how can you determine that there are only 5 values ? Box and whisker only tells the median upper lower quartile/ exteremes ...

[alecmoya]

So are you writing backwards for this video?

[nagendrainuguri]

This video doesn't justify the title, you cannot really find the mean using box plot. Hence it is invalid information.

[isabeltorres]

thanks guys! i I know that in this form of calculation you are using the 5 number summary and having that previous knowledge helped me understand this. ill be seeing more videos soon

[thisisameme]

at least i know that theres someone stupider than me

[nepa]

This is the reason YouTube needs to have dislike button.

[Foxtrottangoabc]

Rachel dont ever Kap your love ! i get it, regardless of the shape of the boxplot with whiskers, do what she says and you get your answer