3rd Quartile of a Grouped Frequency Distributions

This short video details the steps to follow in order to calculate the 1st Quartile value of a Grouped Frequency Distribution

[@Mulalo.]

Oh my goodness thank you so much so helpful.

[@wellimjustakid1202]

omggg thank u veryyy much i really needed this cause we just started statistics😄😊

[@MathsAndStats]

Hi. I'm glad it helped. Please share. 🙂

[@yvonnekiogora9942]

Very helpful thank you very much.

[@lynnetoyoo7274]

very helpful

[@lukhanyomtshingana1962]

Very helpful.

[@Shubh389]

If this table is discrete then the lower limit would be same or 0.5 less. please answer

[@thecolombianrosyleons4557]

I respect the video and learnt a lot out of it. But C is Class Interval and Lower class Boundary is 43.5 not 44

[@jep8480]

Tq. So much helpful

[@frossti1096]

What if the cumulative frequency of a grouped data is equal to 39 instead of exceeding it as in your case it was 40, what if the cumulative frequency of the said data was 39 instead? Would it still be the third quartile?

[@MathsAndStats]

Hi Frossti,. Then you choose the next class interval. You choose the first class interval whose cumulative frequency exceeds the key (3*F/4). There will always be a cumulative that exceeds the key, in particular, the last class. Regards. Jonathan.

[@ritchiebaring5534]

why isn’t the lower boundary 43.5 ?

[@preciousemplamado9937]

It's rounded off

[@freyanimations5040]

(Q3-Q1)/2 right so all I need to do is to substitute the Q3 and Q1 to get the quartile deviation?

[@MathsAndStats]

Yes, the semi inter quartile range (quartile-deviation) = (Q3 - Q1)/2.

[@freyanimations5040]

Thanks for the respond sir ... And thanks for the help

[@elsiefuncion1115]

Hi sir where did you get that 13...?

[@manzuwetakaluwapa6080]

Hello, 57-70 was not supposed to be the Q3 range?

[@MathsAndStats]

Hi Manzuweta. It is not. The video doesn't mention 57-70 as the third quartile class. The video identifies 44-57 as the third quartile class. Kindest regards. Jonathan

[@ruchitham2142]

Thank you so much!

[@mdhayirmohamud595]

thnks sir 4 ur help i can also able now to do Q1 an Q2 by Ef/4 and 2Ef/4

[@MathsAndStats]

Hi Mohamed. Yes, that's the key connection. Well done. Jonathan

[@bubleedas9610]

Can I group an ungrouped data to find the quartiles?

[@trust3689]

You can find quartiles of un-grouped data easily, it's possible. However, if you want to work with grouped data, Yes you can group the data. You just need to decide on your class width and group your data. For instance 1, 1, 8, 7, 6 , 13, 15, 14, 19, 20, the classes of width 5 will be 0-5 = 2 5-10 = 3 10-15 = 2 15-20 = 2 20-25 = 1 From here you can now calculate the quartiles for the grouped data

[@bubleedas9610]

@@trust3689 I used that method in my exam because my professor used it...I wasn't sure so thank you

[@elizapadua6847]

How to find Q4 ?

[@MathsAndStats]

Hi Eliza. Q4 is the largest element in the dataset. Q0 is the smallest, Q1 25th percentile, Q2 50th percentaile, Q3 75th percentile, Q4 if you want to call it that is four quarters which equates to one whole of the data, hence; the largest value. Regards Jonathan

[@mohamedelgogary4764]

What about the 2 nd quartile ?

[@MathsAndStats]

Hi Mohamed, Here you go: a) 1st Quartile: kzbin.info/www/bejne/bobCkJZoZ7uCjKM b) 2nd Quartile (Median): kzbin.info/www/bejne/eGjFnGOLg7aMirc c) 3rd Quartile: kzbin.info/www/bejne/qnPTkKagmtODhaM I hope these help. Please share. Regards. Jonathan.

[@corinaarceo4664]

This is very wrong computation, but the steps is right.

[@venessacastillo2596]

DABABYCAR

[@xwucial]

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[@franshanrussell6051]

I think the lower bound is 43.5 This is absolutely wrong.