A-Level Maths: L1-05 [Data: Median and Quartiles from Cumulative Frequency]

[AceOfHearts]

Thanks Jack. Bumped into an edexcel question which is about engine size vs. Miles per gallon data. And it wanted to identify the outlier using quartiles. How do you ever do that on bivariate data?

So I proceeded on finding quartiles of the dependant (mpg) variable but it was wrong, the answer uses the independent variable (Engine size) to work out the quartiles and the outlier.

But how is that interesting at all as you select your dependant variables yourself, why would there be an outlier based off of that? Super confused.... Your insights as always appreciated. I must be missing something.

[harshkulshrestha]

Could you draw a highest value whisker at 14? Because the value for x is strictly less than 14 so im confused as wouldnt the highest value for x be 13.9 recurring?

[lizziellama]

Why is it that for discrete data you add 1 when calculating median? And why don't you do it for continuous?

[tallula]

Can the median/lower quartile/upper quartile be calculated as a single value from table without plotting a cumulative frequency graph?

[chewypiano]

is line always going thtough all points plotted on cf graph