Question

You have always thought that carbonated drinks taste better in an airplane compared to being on the ground. There is a preference scale that soft drink companies use to test consumers preferences on a 1-100 scale with 1 being they hate the drink and 100 being they love it. From previous studies testing people on the ground, you see that ginger ale has an average preference rating of 40. You randomly sample 6 passengers on a flight and give them ginger ale and measure their ratings and get: 50, 45, 40, 43, 48, 39. You believe people will like ginger ale more in an airplane and want to test it at the p<.05 level.

What is the Research and Null hypothesis?

Answer 1

Below are the null and alternative Hypothesis,
Null Hypothesis, H0: μ = 40
Alternative Hypothesis, Ha: μ > 40

Test statistic,
t = (xbar - mu)/(s/sqrt(n))
t = (44.1667 - 40)/(4.3551/sqrt(6))
t = 2.344

P-value Approach
P-value = 0.0330
As P-value < 0.05, reject the null hypothesis.