Question

Pizza companies are competitive in the amount of time it takes to deliver the pizza. Is there a significant difference in the average time it takes to deliver a pizza between Pizza Hut and Dominos? The following data was collected from a sample of deliveries of both companies; test the hypothesis at a 0.01 level of significance with 10 degrees of freedom(assume unequal variances). Pizza Hut: sample mean = 18.68, sample standard deviation = 1.64, sample size = 5 Dominos: sample mean = 20.23, sample standard deviation = 2.74, sample size = 7 Choose the correct interpretation of results.

		There’s evidence that Pizza Hut delivers pizza faster than Dominos.
		There’s not enough evidence that Pizza Hut and Dominos differ in the time it takes to deliver a pizza.
		There’s evidence that Pizza Hut and Dominos differ in the time it takes to deliver a pizza.
		The proportion of pizzas produced by Pizza Hut is different than Dominos.

Answer 1

test statisitc
t = (18.68 - 20.23)/sqrt(1.64^2/5 + 2.74^2/7^2)
t = -1.864

p-value = 0.0919

As p-value > 0.01, failed to reject H0

There’s not enough evidence that Pizza Hut and Dominos differ in the time it takes to deliver a pizza.

Option B