UnsplashのMaria Tejadaが撮影した写真
This post is following of the above post.
I will calculate confidence interval.
First, I make bootstrapping confidence interval.
I use R infer package.
I use specify(), generte() and calculate() to make a bootstrapping distribution of SELFEMPLOYED mean and EMPLOYEE mean.
Then, I get confidence interval with get_confidence_interval().
95% confidence interval is from 11.2 to 14.3. So, I am 95% confident that the differece of SELFEMPLOYED mean and EMPLOYEE mean is between from 11.2 to 14.3.
Let's visualize that.
Next, I calculate p-value with traditional method(theory based method).
To use traditional method, following two criteria are met.
1. Independent observations
2. Approximately normal
I am not sure that Independent observations criteria, anyway, I will do.
Let's calculate t-static.
t-statistics i1 15.7.
To compute p-value, I need number of observations for each SELFEMPLOYED and EMPLOYEE.
EMPLOYEE has 800 and SELFEMPLOYED has 444 observations.
Now, I can calculate p-value.
I get 0 with traditional method p-value.
In the previous post, I get 0 with simulation based method too.
That's it! Thank you!
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