Outliers - Box and Whisker Plot (1.5 IQR)

Learn how to find which data points are outliers using a box and whisker plot. We discuss the method of working with 1.5 times the interquartile range to find out which data points are outliers. We also discuss how to construct a box and whisker plot by finding the median, lower quartile, upper quartile, maximum and minimum.

Jump to Section of this Video:
0:06 What is an outlier?
0:28 How to create a box and whisker plot
0:36 How to find the median
0:54 How to find the median when there is an even number
1:17 How to find the Upper Quartile and Lower Quartile
1:57 How to graph box and whisker plot on number line
2:33 How to graph the whiskers using the minimum and maximum
2:44 How to find the IQR (interquartile range)
3:08 Use 1.5 IQR to find outliers

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[pedroarellano]

I'm in an online class right now. You explained it much better in less than five minutes than they did. THANK YOU!!

[botlhalekoloje]

I just found you and you explanation is better than my teachers 😸.

[TheLostEngineer-xbiy]

Direct and short explanation, clear, very concise. That's just too perfect for a free video. Thanks!

[athenaa.bosendorfer]

So if 60 is an outlier, do we take it out of the plot and just put a point there? And change the lowest value to 82?

[yurigd]

That's the video I was looking for. Informative and cut-to-the-chase. A deserved thumbs up.

[rainymatch]

the best vid on this specific topic so far, seen a couple. big up!

[khaledmekkari]

Hi, great video, why do we multiple by 1.5 ? and not any other number.

[BVfamily]

Awesome video. Brief and lots of info. Thank you!

[humparepatta]

Hey. Thanks a lot for the video. It is very helpful. I nevertheless have a question. As I understood: the outlier is regarded as an error and therefore not shown as the lowest value. However, its influence on Q1, Q2 and Q3 are still present, right? If we really threw it out, we would calculate a whole different box and whiskers plot. Shouldn't we be using such a new one?

[ayahelhoussieny]

question: why do you multiply 1.5 by the IQR?

[keiniece]

You explained this perfectly. Thank you 😊

[zapatobama]

thanks, but how do we deal with duplicated data? in this scenario for instance. Consider the following set of data;

0.87, 0.88, 0.91, 0.92, 0.86, 0.91, 0.90, 0.93, 0.82, 0.89, 0.87

Construct and interpret a box-and-whisker plot for this data

[scottdiver]

Good video, well explained, thank you.

[SAJBNTM]

I wish you were my teacher in my school!

[shilpanavare]

Nice explanation. Why do we multiply by 1.5

[jaz]

Thank you so so much, saved me once again

[s_w_i_s_s_c_h_e_e_s_e]

Could you please post the formula down here?