### Home > CCA > Chapter 10 > Lesson 10.2.3 > Problem 10-59

Delenn is re-examining the difference in backpacks among different grade levels at her school. (She previously collected data in Lesson 8.1.3.) Now she has collected a new random sample of 100 students to see if there are categorical relationships between carrying backpacks and graduating classes. Homework Help ✎

**Freshmen****Sophomore****Junior****Senior****Backpack**8

16

18

19

**No Backpack**3

6

14

16

**TOTAL****11****22****32****35**Based on her sample, what percentage of students do not carry a backpack at school?

If a junior is chosen, what is the probability they are carrying a backpack?

If a student is not carrying a backpack, what is the probability they are a junior or senior?

Is there a relationship between graduating class and carrying a backpack at school? Show your evidence.

What is the total number of students at Delenn's school?

What is the total number of students who do not carry a backpack?

Use those numbers to find the percentage.

Use the same method as part (a), but limit the numbers to juniors only.

Create a relative frequency table to help you answer this question.

Look at the table you created.

Which classes have a greater frequency of carrying a backpack?