Diskin et al.(in 2003) studied common breath metabolites such as ammonia, aceton
ID: 3171105 • Letter: D
Question
Diskin et al.(in 2003) studied common breath metabolites such as ammonia, acetone, isoprene, ethanol, and acetaldehyde in five subjects over a period of 30 days. Each day, breath samples were taken and analyzed in the early morning on arrival at the laboratory. For subject A, a 27-year-old female, the ammonia concentration in parts per billion (ppb) followed a normal distribution over 30 days with mean 491 and standard deviation 119. What is the probability that on a random day, the subject’s ammonia concentration is between 292 and 649 ppb? Explanations are greatly appreciated.
Explanation / Answer
mean is 491 and standard deviation is 119
P(292<x<649)=P((292-491)/119<z<(649-491)/119)=P(-1.67<z<1.33)
=P(z<1.33)-P(z<-1.67)
=P(z<1.33)-(1-P(z<1.67))
from normal distribution tabke we get 0.9082-(1-0.9525)= 0.8607