I "live" at Wikiversity: https://en.wikiversity.org/wiki/User:Guy_vandegrift
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Wikiversity:User:Guy vandegrift/Editorial tricks
x ¯ = ∑ j w j x j ∑ j w j {\displaystyle {\overline {x}}={\frac {\sum _{j}w_{j}x_{j}}{\sum _{j}w_{j}}}}
