In: Statistics and Probability
Happy Joe’s |
25 |
20 |
21 |
24 |
23 |
24 |
26 |
25 |
21 |
Pizza Hut |
18 |
22 |
18 |
19 |
18 |
22 |
21 |
19 |
20 |
From the Data:
For Weight Lifting: = 23.22, s1 = 2.108, n1 = 9
For Cardio: = 19.67, s2 = 1.658, n2 = 9
(i) Conditions:
(a) Sampling is a simple random sample
(b) samples are independent
(c) Assumed to be from populations that are approximately normal
(ii) Hypothesis:
H0: = : The mean amount of pepperoni in Joes Pizzas is equal to the mean amount of pepperoni in Pizza Hut.
Ha: > : The mean amount of pepperoni in Joes Pizzas is greater than the mean amount of pepperoni in Pizza Hut.
(iii) The Test Statistic to be used is the t statistic for 2 independent samples.
(iv) Critical Value: For Right tail at = 0.05, df = n1 + n2 - 2 = 16 is 1.746
(v) Test Statistic:
We use the pooled variance as s1/s2 = 1.27 (it lies between 0.5 and 2)
(vi) The p value, Right tail at t = 3.97, degrees of freedom = 8 is 0.0005
(vii) The Decision:
Since t observed (3.97) is > tcritical (1.7460, We Reject H0.
Also, since the p value (0.0005) is < (0.05), We Reject H0.
(viii) The Conclusion: There is sufficient evidence at the 0.05 level of significance to conclude that the mean amount of pepperoni in Joes Pizzas is greater than the mean amount of pepperoni in Pizza Hut.