Biology paper 5 doubts

[xyz!]

Whilst scrolling, its now i saw ur post.
Thanks. no i don't do phy.
it indeed helped.
+/-(2*std dev.) is always the case for error bars then?

okay since u've not taken phy...ummm do u noe how to draw the error bars in the graph..?

 

[xyz!]

when choosing the probabilities do you always use 0.05 or does it depend on the confidence interval?

you can either consider the critical value at 0.05 probability and comment on the null hypothesis...orelz u can consider the critical value closest to the calculated value...and then comment...
dat depends on u..

 

[SincerlyMe]

Do we actually have to memorize the formulae, like standard deviation, standard error, T-test ... !?

 

[xyz!]

Do we actually have to memorize the formulae, like standard deviation, standard error, T-test ... !?

the revision guide dat i hav says v dnt hav to memorize them..venevr dey r to b used..dey'll b given in the ppr..

 

[Amy Bloom]

Do we actually have to memorize the formulae, like standard deviation, standard error, T-test ... !?

No you don't have to.

 

[Amy Bloom]

you can either consider the critical value at 0.05 probability and comment on the null hypothesis...orelz u can consider the critical value closest to the calculated value...and then comment...
dat depends on u..

Okay now i have a quest. as you can see in the table the degree of freedom is 19 right? the critical values are between 18 and 20 deg. of freedom, which one do you take and why?

 

[Kumkum]

you can either consider the critical value at 0.05 probability and comment on the null hypothesis...orelz u can consider the critical value closest to the calculated value...and then comment...
dat depends on u..

thnx...

 

[Amy Bloom]

okay since u've not taken phy...ummm do u noe how to draw the error bars in the graph..?

Well i'm unsure but i did it like that
sorry, i quickly made a rough diagram, hope u understand

 

[xyz!]

Okay now i have a quest. as you can see in the table the degree of freedom is 19 right? the critical values are between 18 and 20 deg. of freedom, which one do you take and why?

u can take any value 18 or 20... cos dey allow both...but i hav observed dat v use the higher values for many other past pprs...bt u can use any..dats nt an issue i guess...bt m nt very sure! sry..

 

[xyz!]

Well i'm unsure but i did it like that
sorry, i quickly made a rough diagram, hope u understand

ya ya dis is perfect! gudluck!

 

[Kumkum]

Okay now i have a quest. as you can see in the table the degree of freedom is 19 right? the critical values are between 18 and 20 deg. of freedom, which one do you take and why?

in the examiners report it said candidates should chose the degree that is closest and it was 20 but they also said 18 was acceptable.
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w08_er.pdf.
u can look at the 1st variant paper 5
i think any degree is fine

 

[Amy Bloom]

xyz! and Kumkum thank you!

 

[Kumkum]

xyz! and Kumkum thank you!

welcome!
i have another doubt :
when do we accept or reject the null hypothesis in chi- and t- test?

 

[xyz!]

xyz! and Kumkum thank you!

ur welcum! ty to u as well..!

 

[xyz!]

welcome!
but i have another doubt :
when do we accept or reject the null hypothesis in chi- and t- test?

see..o.o5 is the decider value...if the probability is lower than dis, den we can say dat it is very unlikely dat the null hypothesis is correct..dat is..der IS a significant difference between the means!
hope dat helps!

 

[Amy Bloom]

see..o.o5 is the decider value...if the probability is lower than dis, den we can say dat it is very unlikely dat the null hypothesis is correct..dat is..der IS a significant difference between the means!
hope dat helps!

So, significant difference = accept null hypothesis right?

 

[Kumkum]

see..o.o5 is the decider value...if the probability is lower than dis, den we can say dat it is very unlikely dat the null hypothesis is correct..dat is..der IS a significant difference between the means!
hope dat helps!

ok thnx! i think i got it

 

[Kumkum]

So, significant difference = accept null hypothesis right?

yes thats right

 

[xyz!]

yes thats right

no ur wrong....
null hypothesis= no significant difference between the means...
so significnt diff= reject the null hypothesis

 

[Kumkum]

no ur wrong....
null hypothesis= no significant difference between the means...
so significnt diff= reject the null hypothesis

oh
this is sooo confusing!