help maths question a level statistics

how to do this question? attached

In a histogram the commuting times of a group of individuals, correct to the nearest
minute, are plotted on the x axis.
In this histogram the class 47−50 has a frequency of 48 and is represented by a
rectangle of base 6 cm and height 3.6 cm .
In the same histogram the class 51 − 55 has a frequency of 30 .
Determine the measurements, in cm, of the rectangle that represents the class 51−55.

(edited 1 year ago)

Reply 1

astiaf

please no hint responses. just tell me how to the question straight up please.

Reply 2

Muttley79

Original post by astiaf

please no hint responses. just tell me how to the question straight up please.

No - that's against forum rules ... you must try the question :smile:

Reply 3

astiaf

Original post by Muttley79

No - that's against forum rules ... you must try the question :smile:

yeah mate I tried 100 times for this question. im quite fed up . don't tell me the answer just tell me the way to get the answer . lol

Reply 4

Muttley79

Original post by astiaf

yeah mate I tried 100 times for this question. im quite fed up . don't tell me the answer just tell me the way to get the answer . lol

You know the area that represents 48 so ....

Reply 5

username5991841

Original post by astiaf

yeah mate I tried 100 times for this question. im quite fed up . don't tell me the answer just tell me the way to get the answer . lol

Remember that the area is proportional to the frequency (area = k x frequency). So whatever each 1cm represents in terms of the frequency is the same for every cm. In this case, the question first tells you what the class is and that it is rounded but since time is continuous, find the correct class boundaries to find the base of the bar. Whatever you get for your base represents the 6cm. Find the frequency density which represents 3.6cm. From this find the multipliers so you can figure out what the base and height of the second bar is.

(edited 1 year ago)

Reply 6

astiaf

Original post by Muttley79

You know the area that represents 48 so ....

I thought that you would've thought that I recognised that already after my 100 attempts

Reply 7

davros

Original post by astiaf

I thought that you would've thought that I recognised that already after my 100 attempts

If you've made "100 attempts", surely you could post one of your attempts so that someone can check your logic. And the poster in post #6 has given you a starting point...