Bogleheads:Extension test page

 is an administrative page used to test the proper operation of extensions that have been installed on the wiki.

Code editor
(Wiki admins only) Edit MediaWiki:Print.css and toggle the editor toolbar.

HTML test
This is not an extension, but it checks HTML functionality.

Math
To purge a page with math formulas (refresh the server's cache), append  to the URL.

Suppose random variable X can take value x1 with probability p1, value x2 with probability p2, and so on, up to value xk with probability pk. Then the expectation of this random variable X is defined as

\operatorname{E}[X] = x_1p_1 + x_2p_2 + x_2p_3 + x_3p_4 \ldots + x_kp_k \;. $$ Since all probabilities pi add up to one: p1 + p2 + ... + pk = 1, the expected value can be viewed as the weighted average, with pi’s being the weights:

\operatorname{E}[X] = \frac{x_1p_1 + x_2p_2 + \ldots + x_kp_k}{p_1 + p_2 + \ldots + p_k} \;. $$

RSS feed
http://feeds.feedburner.com/TheSsrnBlogTheSsrnBlog

Google Sheets
Widget:Google Spreadsheet