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AQA percentage change - FEV
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Hiya can I get some help on this question please!
Attachment 739954
Using data from the first second of forced expiration, calculate the percentage
decrease in the FEV for group B compared with group A.
Attachment 739954
Using data from the first second of forced expiration, calculate the percentage
decrease in the FEV for group B compared with group A.
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Ah right sorry
(Original post by QuentinM)
No i can't
(because the attachment is not found apparently-can you reupload?)
No i can't
(because the attachment is not found apparently-can you reupload?)
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#4
FEV is usually quoted with a number to indicate the volume of air exhaled over that number of seconds. I'll assume its 4 seconds in this case.
Group A exhales 5L and group B exhales 2.
For percentage difference, its the difference divided by the original value. So in this case, the difference is 3L, and you divide by 5L, giving you 60% decrease from group A to B.
Group A exhales 5L and group B exhales 2.
For percentage difference, its the difference divided by the original value. So in this case, the difference is 3L, and you divide by 5L, giving you 60% decrease from group A to B.
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#5
Actually, although QuentinM has provided the correct definitions and explanation, the Q states "in the first second", so we need to take FEV1 [which is the value used clinically, incidentally).
So from A to B. there is a reduction from 4.2 to 0.8 = 3.4/4.2 X 100 = 81%
M
So from A to B. there is a reduction from 4.2 to 0.8 = 3.4/4.2 X 100 = 81%
M
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#6
(Original post by macpatgh-Sheldon)
Actually, although QuentinM has provided the correct definitions and explanation, the Q states "in the first second", so we need to take FEV1 [which is the value used clinically, incidentally).
So from A to B. there is a reduction from 4.2 to 0.8 = 3.4/4.2 X 100 = 81%
M
Actually, although QuentinM has provided the correct definitions and explanation, the Q states "in the first second", so we need to take FEV1 [which is the value used clinically, incidentally).
So from A to B. there is a reduction from 4.2 to 0.8 = 3.4/4.2 X 100 = 81%
M
not sure how they got that answer?
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#7
Good morning! (Sorry to bother you while you are dozing away) - you might know that students get up after midday!! 
.
I think the Q is phrased incorrectly (is this an Edexcel Q?).
When they say %age decrease, it clearly implies how much the REDUCTION is for B compared to A. However, it seems they mean "By what %-age of A is B", which is a COMPLETELY DIFFERENT Q.
So, all they are looking for is: 0.8/4.2 X 100 (by reading the y values off the graph you attached at one second for B and A, respectively) = 19%.
IT IS A WELL-KNOWN FACT THAT at A level Biology you earn max marks by keeping things simple and saying the obvious , BUT THAT DOES NOT MEAN THAT EXAM BOARDS SHOULD BULLY STUDENTS BY ASKING Qs WITH INCORRECT English syntax!
BTW, are you doing A2 now OR are you at uni?
.I think the Q is phrased incorrectly (is this an Edexcel Q?).
When they say %age decrease, it clearly implies how much the REDUCTION is for B compared to A. However, it seems they mean "By what %-age of A is B", which is a COMPLETELY DIFFERENT Q.
So, all they are looking for is: 0.8/4.2 X 100 (by reading the y values off the graph you attached at one second for B and A, respectively) = 19%.
IT IS A WELL-KNOWN FACT THAT at A level Biology you earn max marks by keeping things simple and saying the obvious , BUT THAT DOES NOT MEAN THAT EXAM BOARDS SHOULD BULLY STUDENTS BY ASKING Qs WITH INCORRECT English syntax!
BTW, are you doing A2 now OR are you at uni?
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#8
^^^ just came across this q and i still dont get it?!
(Original post by macpatgh-Sheldon)
Good morning! (Sorry to bother you while you are dozing away) - you might know that students get up after midday!!.
I think the Q is phrased incorrectly (is this an Edexcel Q?).
When they say %age decrease, it clearly implies how much the REDUCTION is for B compared to A. However, it seems they mean "By what %-age of A is B", which is a COMPLETELY DIFFERENT Q.
So, all they are looking for is: 0.8/4.2 X 100 (by reading the y values off the graph you attached at one second for B and A, respectively) = 19%.
IT IS A WELL-KNOWN FACT THAT at A level Biology you earn max marks by keeping things simple and saying the obvious , BUT THAT DOES NOT MEAN THAT EXAM BOARDS SHOULD BULLY STUDENTS BY ASKING Qs WITH INCORRECT English syntax!
BTW, are you doing A2 now OR are you at uni?
Good morning! (Sorry to bother you while you are dozing away) - you might know that students get up after midday!!
.I think the Q is phrased incorrectly (is this an Edexcel Q?).
When they say %age decrease, it clearly implies how much the REDUCTION is for B compared to A. However, it seems they mean "By what %-age of A is B", which is a COMPLETELY DIFFERENT Q.
So, all they are looking for is: 0.8/4.2 X 100 (by reading the y values off the graph you attached at one second for B and A, respectively) = 19%.
IT IS A WELL-KNOWN FACT THAT at A level Biology you earn max marks by keeping things simple and saying the obvious , BUT THAT DOES NOT MEAN THAT EXAM BOARDS SHOULD BULLY STUDENTS BY ASKING Qs WITH INCORRECT English syntax!
BTW, are you doing A2 now OR are you at uni?
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#9
basically on the graph you look at the time breathing out and go to one second , you then find the values at which the lines hits one second so like group B which is the dotted line is 0.8 at one second and group A which is the bold line is 4.2 you divide them and then multiple to get the percentage so 0.8/4.2 x100 = 19% . Sorry for the rushed reply but thats the basics of how i did it.
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