11.15 Lab 2: chi-square test for independence

Class Time:

Names:

Student learning outcome:

• The student will evaluate if there is a significant relationship between favorite type of snack and gender.

Collect the data

1. Using your class as a sample, complete the following chart.
   You may need to combine two food categories so that each cell has an expected value of at least 5

   Favorite type of snack

   	sweets (candy&baked goods)	ice cream	chips&pretzels	fruits&vegetables	Total
   male
   female
   Total

2. Looking at the above chart, does it appear to you that there is dependence between gender and favorite type of snack food? Why or why not?

Hypothesis test

Conduct a hypothesis test to determine if the factors are independent

1. $H_o$ :
2. $H_a$ :
3. What distribution should you use for a hypothesis test?
4. Why did you choose this distribution?
5. Calculate the test statistic.
6. Find the p-value.
7. Sketch a graph of the situation. Label and scale the x-axis. Shade the area corresponding to the p-value.

   

8. State your decision.
9. State your conclusion in a complete sentence.

Discussion questions

1. Is the conclusion of your study the same as or different from your answer to (I2) above?
2. Why do you think that occurred?