A sample of 1000 persons screened for a certain disease is distributed
according to height and disease status resulting from a clinical exam
as follows:
DISEASE STATUS
None Mild Moderate Severe Totals
|-------|---------|------------|----------|
Tall | 122 | 78 | 139 | 61 | 400
|-------|---------|------------|----------|
HEIGHT Med | 74 | 51 | 90 | 35 | 250
|-------|---------|------------|----------|
Short | 104 | 71 | 121 | 54 | 350
|-------|---------|------------|----------|
300 200 350 150 1000
What would you estimate from the above table to be the probability
of being medium or short in height and having moderate or severe
disease status?
a. 600/1000 * 500/1000 d. 300/600
b. 300/500 e. 800/1000
c. 300/1000
Difficult Probability Problem
This topic has expert replies
Add all the Medium height and Short height
Medium height = 250
Short height = 350
Probability of Medium height = 250/1000 as 1000 is the total no. of people
Probability of Short height = 350/1000
Probability of Medium or short is 250/1000 + 350/1000 = 600/1000
Moderate = 350
Severe = 150
Probability of Moderate or Severe is 350/1000 + 150/1000 = 500/1000
Hence ,Probability of Medium or short and Moderate or severe is
600/1000 * 500/1000
Ans: A
Medium height = 250
Short height = 350
Probability of Medium height = 250/1000 as 1000 is the total no. of people
Probability of Short height = 350/1000
Probability of Medium or short is 250/1000 + 350/1000 = 600/1000
Moderate = 350
Severe = 150
Probability of Moderate or Severe is 350/1000 + 150/1000 = 500/1000
Hence ,Probability of Medium or short and Moderate or severe is
600/1000 * 500/1000
Ans: A