Probability and Statistics Index > Confidence Intervals This article discusses the 95% confidence interval. In order to understand confidence intervals, you should know what a confidence level is. If you aren’t sure, you may want to view this article first:…

# Confidence Level: What is it?

Probability and Statistics > Statistics Definitions When a poll is reported in the media, a confidence level is often included in the results. For example, a survey might report a 95 percent confidence level. But what exactly does this mean?…

# Confidence Interval Proportion: Find it in Easy Steps

Return to the statistics topic index > Statistics Videos > Confidence Interval Proportion View the video How to Find a Confidence Interval Proportion, or follow the steps in the article below: Confidence Interval Proportion: Overview A proportion is the ratio…

# Using TI-83 to Find Confidence Interval for Population Proportion, p

Probability and Statistics > TI 83 > Using TI-83 to Find Confidence Interval This article shows you how to use the TI-83 to find confidence intervals for a population proportion, p. You may also want to check out these other…

# Confidence Intervals for Two Populations (Proportions)

Probability and Statistics > Confidence Intervals > Confidence Intervals for Two Populations (Proportions) Finding confidence intervals for two populations can look daunting, especially when you take a look at the ugly equation below. It looks a lot worse than it…

# Construct a Confidence Interval with the T-Distribution or Z-Distribution

Probability and Statistics > T-distribution > Construct a Confidence Interval Contents: 1. Confidence Interval (T-Distribution) 2. Confidence Interval (Z-Distribution / Normal Distribution) Construct a Confidence Interval with a T-distribution Watch the video or read the steps below: You may be…

# Confidence Interval For a Sample: Find one in easy steps

Probability and Statistics > T-distribution > Confidence Interval For a Sample Watch the video or read the steps below: Confidence Interval For a Sample: Overview When you don’t know anything about a population’s behavior (i.e. you’re just looking at data…

# How to Find a Confidence Interval: The Easy Way!

Probability and Statistics > Confidence Intervals > How to Find a Confidence Interval How to Find a Confidence Interval: Overview When we talk about a confidence interval (CI), we’re dealing with data. For example, let’s say the manager for that…