# Percentage Error help

#1
Hello, I just need help (in the most simple way possible) with percentage error. Now, I am confident that percentage error is uncertainty/measurement x100.

But, that does not seem to work for the question I tried here:

Describe how the percentage error in the volume measurement would be affected if a 50 cm3 measuring cylinder with an error of +/- 0.5 cm3 had been used repeatedly to measure the 200 cm3 of water.

I did:
(0.5/50)x100= 1 %
1% x 4= 4%, since the measurement would have to be carried out four times, rather than just once if the measuring cylinder is 50cm3, not 200cm3.

I am wrong though, as the answer somehow is 2%...

Any ideas?
0
7 years ago
#2
(Original post by Olax98)
Hello, I just need help (in the most simple way possible) with percentage error. Now, I am confident that percentage error is uncertainty/measurement x100.

But, that does not seem to work for the question I tried here:

Describe how the percentage error in the volume measurement would be affected if a 50 cm3 measuring cylinder with an error of +/- 0.5 cm3 had been used repeatedly to measure the 200 cm3 of water.

I did:
(0.5/50)x100= 1 %
1% x 4= 4%, since the measurement would have to be carried out four times, rather than just once if the measuring cylinder is 50cm3, not 200cm3.

I am wrong though, as the answer somehow is 2%...

Any ideas?
Hmm I'm not sure, perhaps you could try sending a picture of the question?
0
7 years ago
#3
(Original post by Olax98)
Hello, I just need help (in the most simple way possible) with percentage error. Now, I am confident that percentage error is uncertainty/measurement x100.

But, that does not seem to work for the question I tried here:

Describe how the percentage error in the volume measurement would be affected if a 50 cm3 measuring cylinder with an error of +/- 0.5 cm3 had been used repeatedly to measure the 200 cm3 of water.

I did:
(0.5/50)x100= 1 %
1% x 4= 4%, since the measurement would have to be carried out four times, rather than just once if the measuring cylinder is 50cm3, not 200cm3.

I am wrong though, as the answer somehow is 2%...

Any ideas?
You do (0.5*4)/200 not multiply the percentage

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#4
Thank you!
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