The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

S1 Histograms question help needed

Scroll to see replies

Reply 20
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
ooops

mis write on my part ... base = 2


But AREA = base x height = 2 x height = 3.9


so the height = 1.95?
Original post by 95_alim
so the height = 1.95?


:smile:
So you were given the bar for 0-1

1.5 x 5.7 x 300 = 2565

We have worked out the bar for 2-3

2 x 1.95 x 300 = 1170

Now we need the bar for the 5-10 section

6 x height x 300 = 630
Reply 23
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
So you were given the bar for 0-1

1.5 x 5.7 x 300 = 2565

We have worked out the bar for 2-3

2 x 1.95 x 300 = 1170

Now we need the bar for the 5-10 section

6 x height x 300 = 630


height = 0.35?
:biggrin:

Do you understand the principle?
Reply 25
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
:biggrin:

Do you understand the principle?


yeah, you have to first work out the area, then find how much each cm sq represents and then find how many are needed for your frequency then re arrange to find the height?
Yep


Do not forget that you need to think carefully about the group width :smile:
Reply 27
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
:biggrin:

Do you understand the principle?


so the answers are:

a) Width = 2
Height = 1.95

b) Width = 6
Height = 0.35

is this correct?
(edited 12 years ago)
yes
Reply 29
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
yes


hi,

thanks for all your help however i just checked the answers you helped me to figure out and they are all wrong? what have i done wrong?
What answers do they give?
Reply 31
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
What answers do they give?


they gave for the 2-3 group: width is 1.5 and height 2.6

for 5-10 width 7.5 and height 0.28???
oh

well they seem to have ignored the class widths

they have said that 0-1 has a class width of 1 using 1.5cm for the bar
and then they have said that the class width of 2-3 is also 1 giving 1.5 for the bar width
and then 5-10 has a class width of 5 so 5*1.5 gives a bar width of 7.5

then used width x height x 300 = frequency as we did


However ... they have not used the correct class widths
Reply 33
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
oh

well they seem to have ignored the class widths

they have said that 0-1 has a class width of 1 using 1.5cm for the bar
and then they have said that the class width of 2-3 is also 1 giving 1.5 for the bar width
and then 5-10 has a class width of 5 so 5*1.5 gives a bar width of 7.5

then used width x height x 300 = frequency as we did


However ... they have not used the correct class widths


i dont understand why we have to do 5 * 1.5??
Because they are saying that the class width of the first class is 1 and that a width of 1 is shown by a bar width of 1.5

So a class width of 2 would be bar width of 3

A class width of 3 would be bar width of 4.5 etc
Reply 35
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
Because they are saying that the class width of the first class is 1 and that a width of 1 is shown by a bar width of 1.5

So a class width of 2 would be bar width of 3

A class width of 3 would be bar width of 4.5 etc


oh ok... so to work out the height does the procedure remain the same of working out how much each cm sq represents and then see how many u need and then rearrange to get height or is it different.
Original post by 95_alim
oh ok... so to work out the height does the procedure remain the same of working out how much each cm sq represents and then see how many u need and then rearrange to get height or is it different.


Yes the x300 did not change as we used the area of the first bar and the frequency to find that 300
Reply 37
Avatar for 95_alim
95_alim
OP
Original post by TenOfThem
Yes the x300 did not change as we used the area of the first bar and the frequency to find that 300


ok i understand now! thanks

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you