Statistic question involving pulmonary function!

  • Thread starter flip290
  • Start date
  • #1
14
0

Homework Statement


Forced expiratory volume (FEV) is an index of pulmonary function that measures the volume of air expelled after 1 second. FEV is influenced by age, sex and cigarette smoking. Assume that in 45- to 54-year-old nonsmoking men FEV is normally distributed with mean = 4.0 L and standard deviation = 0.5L.
But for 45- to 54-year-old smoking men FEV is normally distributed, with mean 3.5 L and standard deviation = 0.6 L.
Some people are not functionally impaired now, but their pulmonary function usually declines with age and they eventually will be functionally impaired. Assume that the decline in FEV over n years is normally distributed, with mean = 0.03n L and standard deviation = 0.02n L. What is the probability that a 45-year-old non-smoking man with an FEV of 4.0 L will be functionally impaired by age 75?


The Attempt at a Solution


I know that the mean for decline is going to be 0.9L and the standard deviation will be 0.6L because n=30 but I do not know where to go from there.
 

Answers and Replies

  • #2
Ray Vickson
Science Advisor
Homework Helper
Dearly Missed
10,706
1,728

Homework Statement


Forced expiratory volume (FEV) is an index of pulmonary function that measures the volume of air expelled after 1 second. FEV is influenced by age, sex and cigarette smoking. Assume that in 45- to 54-year-old nonsmoking men FEV is normally distributed with mean = 4.0 L and standard deviation = 0.5L.
But for 45- to 54-year-old smoking men FEV is normally distributed, with mean 3.5 L and standard deviation = 0.6 L.
Some people are not functionally impaired now, but their pulmonary function usually declines with age and they eventually will be functionally impaired. Assume that the decline in FEV over n years is normally distributed, with mean = 0.03n L and standard deviation = 0.02n L. What is the probability that a 45-year-old non-smoking man with an FEV of 4.0 L will be functionally impaired by age 75?


The Attempt at a Solution


I know that the mean for decline is going to be 0.9L and the standard deviation will be 0.6L because n=30 but I do not know where to go from there.
What is the number that defines functional impairment? The question is impossible to answer without knowing that.

RGV
 

Related Threads on Statistic question involving pulmonary function!

Replies
3
Views
3K
Replies
1
Views
7K
Replies
1
Views
1K
Replies
4
Views
1K
Replies
13
Views
5K
Replies
22
Views
1K
  • Last Post
Replies
21
Views
965
  • Last Post
Replies
0
Views
6K
Top