Question

1. A consumer products researcher randomly surveyed 900 people and asked them if they try to avoid eating fast food. Of the 505 respondents who were 34 or younger, 199 said they did. Of the 395 who were 35 or older, 186 said they did.

1. Use Minitab to test at the 1% level for a difference in fast food avoidance between these two age groups.
2. Interpret the test results in the context of the data and the question being studied.
3. How might the results of this test be used by a fast food company?

Can you please show your minitab results? Thank you!

Answer 1

Test and CI for Two Proportions

Method

p₁: proportion where Sample 1(34 or younger) = Event

p₂: proportion where Sample 2 (35 or older)= Event

Difference: p₁ - p₂

Descriptive Statistics

Sample	N	Event	Sample p
Sample 1	505	199	0.394059
Sample 2	395	186	0.470886

Estimation for Difference

Difference	99% CI for Difference
-0.0768267	(-0.162397, 0.008743)

CI based on normal approximation

Test

1)

Null hypothesis	H₀: p₁ - p₂ = 0
Alternative hypothesis	H₁: p₁ - p₂ ≠ 0

2.

Method	Z-Value	P-Value
Normal approximation	-2.31	0.021

P-value is greater than 0.01 so, we fail to reject the null hypothesis.

3) Company can conclude that eating habit is independent of age. in other words, people are aware about what to eat or what not to eat