STAT Homework – Conditional Relative Frequencies
Gender and After School Activities
1.
Consider the Rufus King High School data from the previous lesson regarding after-school activities:
Intramural
Basketball
Chess Club
Jazz Band
Not Involved
Total
Males
Females
Total
Calculate the relative frequencies for each of the cells to the nearest thousandth. Place the
relative frequencies in the cells of the following table. (The first cell has been completed as an
example.)
Intramural
Basketball
Chess Club
Jazz Band
Not Involved
Total
Males
Females
Total
1.
2.
3.
4.
Based on your relative frequency table, what is the relative frequency of students who indicated
they play basketball?
Based on your table, what is the relative frequency of males who play basketball?
If a student were randomly selected from the students at the school, do you think the student
selected would be a male or a female?
If a student were selected at random from school, do you think this student would be involved in an
after-school program? Explain your answer.
Survival and Class on the Titanic
On April 15, 1912, the Titanic struck an iceberg and rapidly sank with only 498 or her 1316 passengers
surviving. Data on survival of passengers are summarized in the table below.
Survived
Did Not Survive
Total
First Class Passengers
202
123
325
Second Class Passengers
118
167
285
Third Class Passengers
178
528
706
Total Passengers
498
818
1316
Create a relative frequency table for the survival data
Survived
Did Not Survive
Total
First Class Passengers
Second Class Passengers
Third Class Passengers
Total Passengers
1. What is the marginal relative frequency of passengers who survived? Interpret this value in a
sentence.
2. What is the marginal relative frequency of first class passengers? Interpret this value in a sentence.
3. What is the marginal relative frequency of third class passengers? Interpret this value in a
sentence.
4. What is the joint relative frequency of passengers who survived and were in first class? Interpret
this value in a sentence.
5. What is the joint relative frequency of passengers who were in third class and survived? Interpret
this value in a sentence.
6. Using the six calculations on this page, compare the survival rates between first and third class
passengers.