In: Statistics and Probability
Two opposing opinions were shown to a random sample of 2,150 buyers of a particular political news app in the United States. The opinions, shown in a random order to each buyer, were as follows:
Opinion A: The issue of equal pay is more important than increasing the minimum wage.
Opinion B: Increasing the minimum wage is more important than the issue of equal pay. Buyers were to choose the opinion that most closely reflected their own. If they felt neutral on the topics, they were to choose a third option of "Neutral."
The outcomes were as follows: 50% chose Opinion A, 42% chose Opinion B, and 8% chose "Neutral."
Part A: Create and interpret a 99% confidence interval for the proportion of all US buyers of this particular app who would have chosen Opinion B. (3 points)
Part B: The number of buyers that chose Opinion B and the number of buyers that did not choose Opinion B are both greater than 10. Why must this inference condition be met? (3 points)
Part C: Would a two-sample z-interval for a difference between proportions be an appropriate procedure to find if the difference in proportions between US buyers who would have chosen Opinion B and US buyers who would have chosen Opinion A is statistically significant? Explain why or why not. (4 points)