Question

A market researcher investigated consumer preferences for Coca-Cola and Pepsi before a taste test and after a taste test. The following table summarizes the results from a sample of 200 consumers:

	SOFT DRINK:
PREFERENCE:	Coca-Cola	Pepsi
Before Taste Test	110	90
After Taste Test	118	82

She wanted to perform a chi-square test to see if there is evidence of a difference in preference for Coca-Cola before and after the taste test by allowing a 10% probability of incorrectly concluding that there is a difference when there is in fact no difference.

a) The test will involve _________ degree(s) of freedom.

b) The critical value of the test is _________.

c) The value of the test statistic is _________.

d) Give the above results, should the null hypothesis will be rejected?

Answer 1

I have answered the question below

Please up vote for the same and thanks!!!

Do reach out in the comments for any queries

Answer:

a)

b)

From Chi-squared table, for 10% or 90% confidence we find the critical value as 2.706

c)

Chi-squared value = 0.6528

d)

As the Chi Square test statistics is less than the critical value therefore is accepted.

That is two categorical variables are independent. That is, preferences for soft drink before and after taste test are independent. There is no relationship between them.