Specifications for lactated Ringer's solution, which is used for intravenous (IV) injections, are as follows for each 100mL of solution:

285-315 mg NA+
14.1 - 17.3 mg K+
4.9 - 6.0 mg Ca2+
368 - 408 mg Cl
231 - 261 mg lactate, C3H5O3

How would you make this solution if you have the followng salts: NaCl, KCl, CaCl2, and Na3H5O3.

I haven't worked with a problem like this so i'm not even sure where to start. If i could see this problem worked out with a little explanation, I would be grateful.