The Student Room Group

Class width -Statistics

How do I solve q11 ?
Screenshot (27).png
p.s, the answer isn't mine and idk if its the correct answer
Original post by Leah.J
How do I solve q11 ?
Screenshot (27).png
p.s, the answer isn't mine and idk if its the correct answer


If the minimum in the first class is10, what's the minimum in the second class? And in the third? Hence the only possible answer is?
Reply 2
Original post by ghostwalker
If the minimum in the first class is10, what's the minimum in the second class? And in the third? Hence the only possible answer is?

14 ?
Is it 14-18 ?
Original post by Leah.J
14 ? βœ“\checkmark
Is it 14-18 ? X


You just add on the class width. So, yes, the minimum in the second class is 14. So, what's the minimum in the third class?
Reply 4
Original post by ghostwalker
You just add on the class width. So, yes, the minimum in the second class is 14. So, what's the minimum in the third class?

Why do I care about the 3rd class ? Is its minimum 18 ?
Original post by Leah.J
Why do I care about the 3rd class ? Is its minimum 18 ?


Yes, and so 18 can't be in the second class - that's why you care about the 3rd class!
Reply 6
Original post by ghostwalker
Yes, and so 18 can't be in the second class - that's why you care about the 3rd class!

so it's 14-17?
The class width/length that they're talking about is the one calculated using actual class limits ?
Original post by Leah.J
so it's 14-17?
The class width/length that they're talking about is the one calculated using actual class limits ?


Yes.

Class width is based on class boundaries, and I presume that's what you mean by "actual class limits".
Reply 8
Original post by ghostwalker
Yes.

Class width is based on class boundaries, and I presume that's what you mean by "actual class limits".

By actual class limits I mean the real grade boundaries.
The real boundaries of 14-17 are 13.5-17.5
Original post by Leah.J
By actual class limits I mean the real grade boundaries.
The real boundaries of 14-17 are 13.5-17.5


The question makes no mention of "grades". The classes could be, for example, 14≀x<1814\leq x < 18
Reply 10
Original post by ghostwalker
The question makes no mention of "grades". The classes could be, for example, 14≀x<1814\leq x < 18

I'm confused, why isn't it 10-14 14-18 then
The class width is 4 and the minimum of the 1st class is 10, why isn't the first class 10-14 then ?
Original post by Leah.J
I'm confused, why isn't it 10-14 14-18 then
The class width is 4 and the minimum of the 1st class is 10, why isn't the first class 10-14 then ?


Because the minimum of the second class is 14, so it must be in the second class. 10-14 imples 14 is in the first class.

The question are not very well worded. Where are they from?

Quick Reply

Latest