A-Level Maths: L3-04 [Data: Estimating the Mean from Grouped Data]

[nourhansherif]

I’m confused as to why for the last one, you didn’t work out the mid point for one less than the end point... for example, the top one it says 5_<x<8, it’s not equal to 8 so why don’t you work out the midpoint for 7 not 8?

[saadahmed]

Hello, could you show us how to use the casio CG50 to find the mean etc of grouped continuous data like this?

[alanmohan]

Would you have to show your working for this question or will it be okay to just use your calculator

[RB-nhom]

say if it wasn't grouped data and we had (£) x=8, 9, 10, 11, 12 and respectively freq=14, 8, 28, 15, 20. and we were asked to find number of students that received more than £11.57 would this be rounded up and would this value lie in x=11 or x=12.

[tahirnaeem]

Hi Jack for the Age example, if you were 16 then that would fall into the next interval, so why not take the midpoint of 10 to 15 instead of 10 to 16? Are we saying its upto 16 but not including that value and we round down ?

[saifulsaiful]

Will you loose method marks if you use the calculator to find mean, fx^2, etc.?

[Jack-werx]

Hi Jack, For the final frequency table, why is it not 5+7.9/2 for the midpoint, if 8 is not included in that data range
Many Thanks

[ismailrahman]

Hi jack. For what things e.g. length will you write the class intervals like you've done for length and for what things e.g. age will you write the class intervals like you've done for age? thanks in advance.

[awdast]

hi jack, is age in years considered a continuous variable then?

[kaijss]

would you seriously lose marks in an exam if you didnt consider the age interval and just used the mid point of the 2 pieces of data? (EG found the mid point of 10-15 rather than 10-16)