Question

2. Difference between two population means (two independent samples). The data on the estimated average price for a 6-ounce can of tuna, based on prices paid nationally in supermarkets, is available in the file “Tuna”. Two types of tuna are considered: light tuna in water and light tuna in oil. Test if the price of tuna in water is significantly less than the price of tuna in oil.

Light Water	Light Oil
0.99	2.56
1.92	1.92
1.23	1.3
0.85	1.79
0.65	1.23
0.69	0.62
0.6	0.66
0.53	0.62
1.41	0.65
1.12	0.6
0.63	0.67
0.67
0.6
0.66

Using Minitab, generate output for this test. (Use α = 0.05)

1. State the two hypotheses you are using in this test.
2. What is the calculated test statistic? What is the critical value (using a T-table)? Draw a sketch of the rejection region.
3. What is the p-value for the test?
4. What can you conclude about the prices for different types of tuna based on the test? Discuss your conclusion.

Answer 1

From MINITAB output

a) The two hypothesis in the test is

b) The test statistics t = -1.16

c) P-value = 0.130

d) Given

then P-value = 0.130 > 005

so, fail to reject H₀

hence there is no evidence that the price of tuna in water is significantly less than the tuna in oil