Hi,
I got 1 mark deducted because of rounding. It says "Give your answer to the nearest hour". My computation comes to 13.4 hour so I round down to 13 and was marked wrong. Teacher says 14 hour is the correct answer. Why? Also if it is 13.05 hour what then? Thanks.
Originally posted by Jt061952:Hi,
I got 1 mark deducted because of rounding. It says "Give your answer to the nearest hour". My computation comes to 13.4 hour so I round down to 13 and was marked wrong. Teacher says 14 hour is the correct answer. Why? Also if it is 13.05 hour what then? Thanks.
Perhaps you would like to state the full question here so that we can have a look at it.
OK, here is the question.
An experiment was carried out to study the growth of a micro-organism. The population, P, present at t hours after the initial observation is given by P = 310 + 150 e ^(0.2 t) .
Calculate the time taken for the pop of the micro organism to reach 2500. Give your answer to the nearest hour. My answer is 13.4 hour
Calculate the average rate of increase of the pop on the first 24 hours. (BTW , how to do this one? Answer is 753) Thank you.
OK, I found the answer to my question.
at t=0, P = 460
at t=24, P = 310 + 150 e^(0.2 x 24) = 18537
Ave increase in 24 hours is (18537 - 460) / 24 = 753
wad lvl is this?
seems very engineering math to me.
Originally posted by Jt061952:OK, here is the question.
An experiment was carried out to study the growth of a micro-organism. The population, P, present at t hours after the initial observation is given by P = 310 + 150 e ^(0.2 t) .
Calculate the time taken for the pop of the micro organism to reach 2500. Give your answer to the nearest hour. My answer is 13.4 hour
Calculate the average rate of increase of the pop on the first 24 hours. (BTW , how to do this one? Answer is 753) Thank you.
For such questions you will always have to round up regardless whether its 13.01 or 13.99 simply because at 13.0, the amount of microorganism is less than what is required. Only at above 13 hrs is it enough and thus the nearest hr is 14.
This requires abit of logic and not plain maths rounding up/down.
Originally posted by dkcx:For such questions you will always have to round up regardless whether its 13.01 or 13.99 simply because at 13.0, the amount of microorganism is less than what is required. Only at above 13 hrs is it enough and thus the nearest hr is 14.
This requires abit of logic and not plain maths rounding up/down.
really meh?
lets say this is Engineering math diploma level, which i took, ive never learn anything about microorganism leh.
Originally posted by maskedangel:really meh?
lets say this is Engineering math diploma level, which i took, ive never learn anything about microorganism leh.
The qn very hard meh? Just sub in values only
Originally posted by dkcx:The qn very hard meh? Just sub in values only
regarding the rounding off part.
Originally posted by maskedangel:regarding the rounding off part.
I thought its consider logic
Originally posted by dkcx:For such questions you will always have to round up regardless whether its 13.01 or 13.99 simply because at 13.0, the amount of microorganism is less than what is required. Only at above 13 hrs is it enough and thus the nearest hr is 14.
This requires abit of logic and not plain maths rounding up/down.
mhmm, gotta agree.
oh my, my bad . . .
this is under logararithm and indices in sec 3 A maths ......why 13 h not allow as 13.4 hr den bacterial up to given amt..........but 13 nrs still short