A-Level Maths: L1-07 [Data: Median and Quartiles from Histograms]

[satwikasaran]

I have a few questions! How can you be sure that the median is 8? For example if there a 20 data points in the 6 to 8 interval, isn’t it possible that all the 20 of them are 7? Furthermore, going by what you said... In that class interval, x is greater than or equal to 6 but less than 8, so how can the median be 8, as the 25th value must still be in that interval, but you can never be sure what number it is (as it’s grouped)? Sorry... I am a little confused, please reply!

[krishmakkar]

Hello, just a question, why can you not start your interpolation from the second class width in order to find the LQ? Doing ((2/10)*7.5)+6.

[girlonline]

For interpolation in the “Pearson edexcel statistics and mechanics year 1/as” they say to use 5.5 and 9.5 for an interval of E.g 5-9 instead of 5 and 9 could you explain this I’m so confused

[privatecaller]

Hello Sir,
How do you determine the values to use when interpolating? For grouped continuous data, I would've thought that, for example, the group 6<x<8 would use the values 5.5 and 8.5 due to being continuous data. Please assist me with this.

[katt]

How can the median be 8 when we know that it is in the group since in that group x is les than 8 and greater than 6 so if it was 8 that would be the next group down?

[createa]

Hello, how do you find the mean of a histogram?

[nanoyt]

Sir do we need to know this for aqa ??

[harrysmith]

Can the constant k in a proportion ever be negative?