how do you do this question?

http://filestore.aqa.org.uk/subjects/AQA-43651H-QP-JAN13.PDF
This is a past paper. look at question 19 and you will see the problem i have.please help

Reply 1

kfcisopen

It's quite hard, what i think you have to do is firstly work at frequency density using the class width + total frequency of 500. To do this you have to look at the different class widths and multiply each one by a particular number, bearing in mind that this number will differ due to different class widths and then using the different numbers which also work on the y-axis. From this you just find the number thats under 10 as then you've god f.density and class width

Reply 2

Anonymous 14

Use the formula:

frequency=frequency density X class width

500. = x. X 14
X. =500/14
=36

x. =36/20
=1.8

so each box on the histogram represents 1.8

1.8/5 =0.36

each line of a box equals 0.36

3 lines per box

3 X 0.36 =1.08

1.08 X 4 =4.32

i think this is right but it might be worth checking a mark scheme. My maths is a bit rusty but I hope I helped you.