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Question
NARRBEGIN: SA_80_83A marketing research consultant hired by Coca-Cola is interested in determining if the proportion of customers who prefer Coke to other brands is over 50%. A random sample of 200 consumers was selected from the market under investigation, 55% favored Coca-Cola over other brands. Additional information is presented below.
| Sample proportion | 0.55 |
| Standard error of sample proportion | 0.03518 |
| Z test statistic | 1.4213 |
| p-value | 0.07761 |
(A) If you were to conduct a hypothesis test to determine if greater than 50% of customers prefer Coca-Cola to other brands, would you conduct a one-tail or a two-tail hypothesis test? Explain your answer.
(B) How many customers out of the 200 sampled must have favored Coke in this case?
(C) Using a 5% significance level, can the marketing consultant conclude that the proportion of customers who prefer Coca-Cola exceeds 50%? Explain your answer.
(D) If you were to use a 1% significance level, would the conclusion from Question 82change? Explain your answer.
Answer
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