# Math225 Week 4 Assignment: Contingency Tables

Question

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?

 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

Question

Fill in the following contingency table and find the number of students who both play sports AND play an instrument.

 Students Play an instrument Do not play an instrument Total Play sports 57 Do not play sports 10 Total 67 99

Question

Fill in the following contingency table and find the number of students who both have a cat AND have a dog.

Question

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.

Question

Given the contingency table below, determine the marginal distribution of breakfast and lunch. Round your answer(s) to the nearest whole number. Select all that apply.

 Food Bread Rice Total Breakfast 122 189 311 Lunch 420 263 683 Total 542 452 994

Question

Researchers wanted to study if wearing cotton clothes is related to depression. They surveyed a large group of people. The data are shown in the contingency table below. What is the relative risk of wearing cotton clothes for those who are depressed? Round your answer to two decimal places.

Question

Given the contingency table below, determine the marginal distribution of the bread and rice. Round your answer(s) to the nearest whole number. Select all that apply.

 Food Bread Rice Total Breakfast 122 189 311 Lunch 420 263 683 Total 542 452 994

Question

Given the contingency table below, determine the marginal distribution of the toys’ shapes. Round your answer(s) to the nearest whole number. Select all that apply.

 Toys Black White Total Round 3 7 10 Square 5 2 7 Total 8 9 17

Question

Researchers want to study whether or not a fear of flying is related to a fear of heights. They surveyed a large group of people and asked them whether or not they had a fear of flying and whether or not they had a fear of heights. The data are shown in the contingency table below. What is the relative risk of being afraid of flying for those who are afraid of heights? Round your answer to two decimal places.

Question

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 relative risk of flying for those birds that have long beaks? Round your answer to two decimal places.

Question

Fill in the following contingency table and find the number of students who both watch comedies AND watch dramas.

Question

Fill in the following contingency table and find the number of students who both have a cat AND have a dog.

 Students have a dog do not have a dog Total have a cat 49 do not have a cat 17 Total 46 98

# Solution:

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?

 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

Fill in the following contingency table and find the number of students who both play sports AND play an instrument.

 Students Play an instrument Do not play an instrument Total Play sports 57 Do not play sports 10 Total 67 99