We have calculated a confidence interval based on a sample of size n = 80. Now we want to get a better estimate with a margin of error that is only one-fourth as large as the previous margin of error. How large does our new sample need to be? 20 320 640 1280 1600
Added by Mario H.
Step 1
This means that as the sample size increases, the margin of error decreases, and vice versa. Second, we know that we want the new margin of error to be one-fourth as large as the previous margin of error. This means that we need to multiply the previous sample Show more…
Show all steps
Close
Your feedback will help us improve your experience
Madhur L and 76 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
When we want $95 \%$ confidence and use the conservative estimate of $p=0.5,$ we can use the simple formula $n=1 /(M E)^{2}$ to estimate the sample size needed for a given margin of error ME. In Exercises 6.40 to 6.43, use this formula to determine the sample size needed for the given margin of error. A margin of error of 0.04 .
Inference for Means and Proportions
Confidence Interval for a Single Proportion
When we want $95 \%$ confidence and use the conservative estimate of $p=0.5,$ we can use the simple formula $n=1 /(M E)^{2}$ to estimate the sample size needed for a given margin of error ME. In Exercises 6.40 to 6.43, use this formula to determine the sample size needed for the given margin of error. A margin of error of 0.05 .
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD