Confidence Intervals We Use Everyday

Introduction

Did you know confidence intervals are also used to project reliability in consumer products? We use confidence intervals in our daily lives, from consumer ratings to election projections. Seeing this data helps us make decisions on the best option to choose. If, for example, one brand of refrigerator has a 17% chance of needing repair in the first three years. A different brand may have a 3-year repair rate of 19%. If a footnote says, "differences of more than 4% are meaningless," we can conclude that the repair rates really are not that different! However, any refrigerator with a repair rate more than 4% higher than 17% is more likely to need repair in the next three years.

Locate & Complete

For this discussion, analyze a population confidence interval that you may have used in your work or researched on the internet.

Provide a link to the data and respond to the following questions:

• How did this data help in the decision-making process?
• What was the population confidence interval?
• What was the margin-of-error?