A.7 ci for proportion

255 views
219 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
255
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
2
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

A.7 ci for proportion

  1. 1. Large Sample Confidence Interval for a Proportion
  2. 2. CI for a sample proportion (p) Estimation Requirements Constructing a CI for a sample proportion are valid when these conditions are met: 1. sampling method is simple random sampling (SRS) 2. sample includes at least 10 successes and 10 failures ( np > 10 AND nq > 10) where q=1-p How to find CI for a proportion: (method same as described before) 1. sample statistic (use sample proportion to estimate population proportion) 2. CL (90%, 95%, 99%) 3. ME= CV x SD or ME= CV x SE 4. Specify CI: sample statistic + ME written as: (Sample Stat – ME, Sample Stat + ME)
  3. 3. Variability of Sample Proportion • Must compute standard error(SE) of sampling distribution in order to construct a CI for the sample proportion • When the population size is at least 10 times larger than the sample size, SE can be approximated by: ** this is found on table under single sample - proportion

×