*Biology Paper 5 tips*

[PhyZac]

to find the value of X^2 for the chi squared test.. you add up all the (O-E)^2 / E values and divide it by what? n+1?

You add.

No dividing.

 

[Lalitha Ambighai]

thanks that's really helpful !!

you're most welcome... Best Wishes!!!

 

[knowitall10]

First two posts are amazing and incredibly helpful
Thanks a lot knowitall10. May Allah bless you and give you good grades

No problem AAmeen..and may you get the Highest grades in both worlds inshAllah

 

[Xainab]

aaaa so if its standard error you ,multiply by root n
ok thanks

Divide by root n.

 

[connor4666]

Hey guys. I'm sorry if this has been answered before, but I have a question. So lets suppose I have a value of lets assume 50 and a standard error of lets says 2. How would I make the error bar for it? Do I add the '2' on both sides? As in up and down of the '50' mark. Or do I divide it by 2 and add '1' on both sides??
Please help me out guys!!

 

[PhyZac]

Hey guys. I'm sorry if this has been answered before, but I have a question. So lets suppose I have a value of lets assume 50 and a standard error of lets says 2. How would I make the error bar for it? Do I add the '2' on both sides? As in up and down of the '50' mark. Or do I divide it by 2 and add '1' on both sides??
Please help me out guys!!

You multiply with 2 getting 4 in your example. And then you make 4 above and 4 below the 50

 

[connor4666]

You multiply with 2 getting 4 in your example. And then you make 4 above and 4 below the 50

See, I don't get that. Why do you multiply the standard error by 2? If it has a value of 2 shouldn't it be simply +/- 2?

 

[PhyZac]

See, I don't get that. Why do you multiply the standard error by 2? If it has a value of 2 shouldn't it be simply +/- 2?

I wish it was that simple, but what to do, the books say we have multiply, and so we should.

 

[connor4666]

I wish it was that simple, but what to do, the books say we have multiply, and so we should.

I don't know man. I don't think so, but you might be right.
I hope somebody confirms what you're saying!

 

[Irfan1995]

Z-test is not in syllabus
T-test is

Actually, one of the Z-tests is the student's t-test.

 

[PhyZac]

I don't know man. I don't think so, but you might be right.
I hope somebody confirms what you're saying!

I am sure brother. I was also confused, but confirmed it.

Check you book and check internet also.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/page-16#post-602520

 

[railey]

How do u draw the histogram from may june 2007 paper 5 question 1 a)
Do u do the same as in maths, to calculate the frequency density?

 

[D0cEngi]

Plz anyone tell me how to calculate the degrees of freedom in t-test..?

 

[knowitall10]

Plz anyone tell me how to calculate the degrees of freedom in t-test..?

no of samples - 1

 

[Soldier313]

Aoa wr wb
I need some help with a few qns

For qn 2 c of this paper, why does the rate of loss increase??

http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s12_qp_52.pdf
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s12_ms_52.pdf

____________

For qn 2 a of this paper, we need a stain, someone previously told me we use Giemsa, but i was just wondering, is there another one that's mentioned in the syllabus?

http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s11_qp_51.pdf
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s11_ms_51.pdf
____________

For qn 2 d i of this paperm can someone please elaborate the ms answer ?

http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s11_qp_52.pdf
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s11_ms_52.pdf

Thank you so much

 

[Irfan1995]

I'm not sure if you guys take any statistics. But if you do, you will know that in a normal distribution (one of the condition of the t-test), 68% of the data lies within one standard deviation from the mean, and 95% of the data lies within two standard deviations from the mean, and 99.7% of the data lies within three standard deviations from the mean.

In Biology, we're more concerned with something called the '95% confidence interval'. This is the range that we are 95% sure that the data's mean lies within it. In a normal distribution, we are 95% confident that the means of other sets of data lies within two standard deviations from the initial/calculated mean. We draw our error bars around that range.

Example: In a class, we have a mean height of 165 cm with a standard deviation of 5 cm. We draw the error bars from 165 - (2 x 5) to 165 + (2 x 5). This means that the error bars will extend from 155 cm to 175 cm.

 

[knowitall10]

Aoa wr wb
I need some help with a few qns

For qn 2 c of this paper, why does the rate of loss increase??

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_52.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_ms_52.pdf

____________

For qn 2 a of this paper, we need a stain, someone previously told me we use Giemsa, but i was just wondering, is there another one that's mentioned in the syllabus?

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_51.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_ms_51.pdf
____________

For qn 2 d i of this paperm can someone please elaborate the ms answer ?

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_52.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_ms_52.pdf

Thank you so much

oh boy....

 

[connor4666]

I am sure brother. I was also confused, but confirmed it.

Check you book and check internet also.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/page-16#post-602520

Looks good bro. Thanks!

 

[Soldier313]

oh boy....

uh-oh :/ sorry knowitall I always post questions in clusters :/

 

[knowitall10]

uh-oh :/ sorry knowitall I always post questions in clusters :/

Oy AOA WR WB
Emma13 accepted Islam..congratulate her..mashAllah =')
And it's ok....i'm working out your question