Balanced equation for Schweizer's reagent production?

In Thompson's [*Illustrated Guide to Home Chemistry Experiments*](http://shop.oreilly.com/product/9780596514921.do) the chemical formula for Schweizer's reagent is represented as $\ce{[Cu(NH3)4](OH)2}$ (although [Wikipedia](https://en.wikipedia.org/wiki/Schweizer%27s_reagent) represents it as $\ce{[Cu(NH3)4(H2O)2](OH)2}$ ).


Using Thompson's formula, it seems a balanced equation for producing Schweizer's reagent by disolving copper (II) hydroxide in aqueous ammonia would be:


$\ce{Cu(OH)2 (s) + 4 NH3 (aq) -> [Cu(NH3)4](OH)2 (l)}$


This indicates a ratio of 1:4 for copper hydroxide to ammonia. 


Is the above balanced equation, and the indicated 1:4 ratio, correct? If not, what might be a correct representation?


(Note: This is a more specific question related to a [broader question about Schweizer's reagent production](https://chemistry.stackexchange.com/q/121944/84295).)


