Confidence Interval and Sample Size
The applet below illustrates the concept of constructing confidence intervals for proportions (a 1-proportion z-interval).
Set the population proportion, sample size, and confidence level using the sliders. There are 100 confidence intervals (horizontal segments) at your chosen confidence level, based on 100 random
samples of your chosen sample size, from a population with your chosen proportion.
On average, the percentage of confidence intervals that contain the population proportion (p) will be equal to the chosen confidence level.
Q.1 Change the slider n - the sample size. Describe the relationship between the sample size and the length of confidence intervals (horizontal segments.) Scroll down to answer more questions.
Q. 2. Change the slide Confidence Levels. Describe the relationship between: a. The number of red segments and the confidence levels. b. The confidence levels and the length of confidence intervals.