Contingency tables
1. Researchers wanted to study if couples having children are married. They surveyed a
large group of people. The data are shown in the contingency table below. What is
the relative risk of having c
...
Contingency tables
1. Researchers wanted to study if couples having children are married. They surveyed a
large group of people. The data are shown in the contingency table below. What is
the relative risk of having children for those who are married? Round your answer to
two decimal places.
Children no children total
Married – 97 35 132
Not married- 68 71 139
Total 165 106 271
1.50
The probability that someone who is married has children is 97/132. The probability
that someone who is not married has children is 68/139. The relative risk is
then 97/132 divided by 68/139≈1.50. This means that in this survey, people who are
married were 150% as likely to have children as people who are not married
2. A survey of 155 employed citizens was conducted and the results are shown in the
table below. Given that a randomly selected survey participant does not work in an
office, what is the probability that this person works on Saturday?
Enter your answer as a fraction.
Does not Work in an Office Works in an Office Total
Does not Work Saturday 32 62 94
Works Saturday 14 47 61
Total 46 109 155
7/23
The total number of those not working in an office is 46. Of these, 14 work on
Saturday. Therefore, the probability that a randomly selected person from those not
working in an office works on Saturday is 14/46=7/23
3. Researchers wanted to study if having a long beak is related to flight in birds. They
surveyed a total of 34 birds. The data are shown in the contingency table below.
What is the odds ratio for birds having long beaks being able to fly against birds not
having long beaks being able to fly? Round your answer to two decimal places.
Flies Does not fly Total
[Show More]