Confidence Intervals

Prior to beginning work on this assignment, read Section 8-4: Concepts in Hypothesis Testing and Confidence Interval Estimation of the Business Analytics: Data Analysis and Decision Making (8th edition) textbook.

You may find it helpful to review the video

and the webpage

.

In this weeks reading, the text discusses different types of samples and their distributions, sampling errors, probabilities, and confidence intervals. Using Excel, complete the following problem. This is similar to Problem 33 in Chapter 8.

Problem: You have been assigned to determine whether more people prefer Coke or Pepsi. Assume that roughly half the population prefers Coke and half prefers Pepsi. How large a sample do you need to take to ensure that you can estimate, with 90% confidence, the proportion of people preferring Coke to within 5% of the actual value? Show all of your work.

In your Excel spreadsheet,

• Identify the sample size.
• Utilize Excel support tools.
• Present any equations utilized.