Question

1. 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. Find the corresponding critical value(s) at a 0.01 level of significance.

   		±2.575
   		±2.33
   		±2.764
   		±3.169

Answer 1

Solution :

df = 9.8~10

= 0.01

/ 2 = 0.01 / 2 = 0.005

t _0.005,10 = 3.169

Critical value = 3.169