mean resting breath question(a level biology)

Hi ,
I have attached a photo of the question .The answer should be between 12.8 and 13 .Could you help me understand the steps that I need to do ,to get that answer ?

(edited 7 months ago)

Screenshot 2023-09-10 at 20.25.53.jpg111.7KB

Reply 1

BankaiGintoki

Original post by 00vicky00

Hi ,
I have attached a photo of the question .The answer should be between 12.8 and 13 .Could you help me understand the steps that I need to do ,to get that answer ?

First identify the number of breaths that are at rest, not maximum inhalation/exhalation
Second is the time. You are told the entire trace is for 1 minute, but there are no x axis labelled so
Measure the entire horizontal length of the trace with a ruler (B cm)
Measure the horizontal length of the resting breaths you have, so x resting breath (A cm)
A/B x 60 to find the number of seconds taken up to that moment
For example, if it took 3 breaths in 13 seconds you would do 3 x 60/13 for breaths per minute

Nevermind, I finally noticed you can use the graph for the times (I had to zoom in close to see it)

Now just count the number of resting breaths in x seconds,
Than multiply the number of resting breaths by 60/x.
The more resting breaths you count, the lower your percentage uncertainty, so dont count just one or two (as the seconds will be smaller, so the error in 60/x becomes larger)