Help with this maths questions please?

Zahra199

Please help me with this box plots question (the traffic police statement one).
Thanks :smile:

Disclaimer: I'm not wanting the answer just an explanation of how to get it and why.
:smile:

I'll attach an image below.

Untitled.jpg72.5KB

Reply 1

the bear

it is not a boxplot ?

use the cumulative curve to find the number of people traveling over the speed limit

make it into a %...

Reply 2

anonwinner

Firstly you need to work out 20% of 60. This will answer the first question.

Then, on the graph go to the point on the x axis where the speed is 130km/h and draw a vertical straight line up until it meets the cumulative frequency curve. Then draw a horizontal line from this point towards the y axis to find the cumulative frequency. You then take away this cumulative frequency away from the total cumulative frequency - 60 - to find the number of cars driving over 130km/h

Reply 3

Chittesh14

This is a very simple question. However, you might need to read it a few times to understand what it's asking you to do. First of all, it's saying 20% would suggest more than .... cars, meaning 20% of the total number of cars go above the speed limit. To find out what that number is, you do 20% of 60. Then, the next part says, the graph reads ... cars, which means you have to find out how many cars go above the 120 km/h speed limit on the graph. To do this, you draw a horizontal line at 120 km/h and then a vertical line at the last car which is at 120 km/h, this shows the amount of cars that are not breaking the speed limit. Then, you subtract that number from the total amount of cars, which gives you the number of cars breaking the speed limit.