# OECD Nuclear power plants data analysis 2 - Getting Confidence Interval using R with infer package UnsplashEean Chenが撮影した写真

This post is following of the above post.
I will calculate confidence interval in this post.

There are two ways to calclulate confidence interval, one is bootstrap method and the other is traditional(formula) method.

To do bootstrap, I load infer package. Firstly, let's to bootstrap. I made bootstrap distribution of mean.

let's get averge num. Let's visualize bootstrap ditribution and observed average.  To get confidence interval, I use get_confidence_interval() frunction. So, with bootstrap method, 95% confidence interval is 8.89 ~ 30.1.

Then, let's calculate confidence interval using traditional(formula) method.

We need some components to calculate confidence interval. then, I can calculate confidence interval. Using t.test() function is the easiest way to get traditional confidence interval. Now, let's compare bootstrap confidence interval and traditional(formula) confidence interval.  I see bootstrap confidence interval is norrower than traditional(formula base) confidence interval.

That's it. Thank you!

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