A-Level Maths: L3-05 [Data: Estimating the Median from Grouped Data]

[dylendra]

Explained it so well, you should be a maths teacher

[bcg]

Nice video, couldn't have understood median any better.

[e_bi]

youre a lifesaver!! this is so much easier than the method i was taught, it works better for me to visualise it like this.

[harleensandhu]

Thank you so you cleared all my doubts

[aryanshah]

Sir, why do we use 15.5 and 19.5 as the boundaries for the first question? Why do we not use 15 and 19?

[anonymooseuser]

Sir, why do you use 31 as the boundary for the second question? In an exam I would likely use 21-30 or 9 as my class width instead of 21-31

[shumailahmad]

Brilliant video!!!
I noticed that the total frequencies were always even. If the total frequency was 101 for example, would the median value be the 50.5th value for grouped data?

[keiransingh]

Hi i was going over this topic for my mock and i see that sometimes some other people on YouTube add one to the total frequency before dividing by 2 to get the midpoint just wondering which method is right. (I am doing the Edexcel spec). Thanks.

[caglaadalier]

for the third example, i solved using the interval 22<x<50 and the 20-39 cumulative part, and still got the same answer, is this just a coincidence, or would that have been a valid method too?

[fizlyx]

After watching this video, I did the Edexcel S1 June 2013 Question 4(b) and I used this method and it gave me 20.7 however the answer was 22.7 but using a similar method. Could you please try the question for yourself to see what I have done wrong and reply as soon as possible please?

[peter_ade]

Thank you very much, this helped my properly understand! I was recommended this channel!!

[jamalpov]

With edexcel, the text book says n+1/2 but when doing exam questions specific to edexcel they require just half and not adding 1. Which one should i stick to, to be able to get the full marks on an AS edexcel exam.

[abdoweisa]

Idk how but you always make me understand things no other teacher can 😂

[debating]

Hi, I have a question. In the 3rd grouped data table why do we write 3 for 8? Isn't it supposed to be 20? Because it says 5<x<8, meaning 8 doesn’t belong to that class but rather belongs to 8<x<22

[oliverbrogan]

When using linear interpolation on discrete data, do you have to round to remove any decimal places?

[jackhatton]

How can the 3rd value be 8?

If there are 3 values in the first class, and the class states that x < 8

In my head, my own logic tells me the first three values would be 5, 6, 7. Is there something flawed with my way of thinking about this?

[sarahadams]

Why do you only do the bounds on the first one? Why not the last one?

[ryder]

Hi on your website I’m going through the teaching order for year 1 and section 28: b) only has L3-04 and L3-05 and then in section 28: c) it jumps to L3-10 (comparing data sets) so I can’t find L3-06, L3-07 and L3-08 unless they’re in another area of the teaching order thanks

[abcc]

in GCSE is the position of the median n+1/2?

[AKD-lfng]

Hi!! on the second question, why is it going up to age 31 and not 30??