Question

Researchers examined the bottled-water phenomenon and preference of water types. One hundred fifteen subjects participated in double-blind taste tests of three different bottled water brands (Fiji, Aquafina, and Sam’s Choice) and tap water. Fifteen people preferred the tap water, 29 Aquafina, 47 Fiji, and 24 Sam’s Choice. At the 1% significance level, do the data provide sufficient evidence to conclude that the four different water types are not equally likely in preference?

Complete the table below

Category	Proportions	Ob. Freq. O	Expected Freq. E	Diff. (O – E)	Sq. of Diff (O – E)^2	Chi-Sq. Subtotal [(O – E)^2]/E
Tap Water	0.25	15
Fiji	0.25	47
Aquafina	0.25	29
Sam’s Choice	0.25	24
		n =				Total =

Then use (a) the critical value approach and (b) the P-value approach

(Note: Conclusion should be the same no matter the approach used)

For each test,

i) State your null and alternative hypotheses.

ii) What is the significance level?

iii) What is the chi-square test statistic?

iv) What conclusion can you draw based on the data? Write a sentence. Include your test results.

Answer 1