K, here we go. First, we look at Lucario's base stats: 70/110/70/115/70/90 in order of HP/Atk/Def/SpAtk/SpDef/Speed.
Besides HP, the formula to calculate stats with 0 EVs or IVs at level 100 is double the base stat plus 5. So, your stats would now be x/225/145/235/145/185.
For HP, the forumla to calculate it is double the base stat plus 110. So your stats would now be 250/225/145/235/145/185.
Now, to calculate EVs and IVs. IVs add itself to the stat, and EVs add itself divided by 4 to the stat, rounding down. Let's start with IVs. Since you have 31 IVs in every stat, your stats would increase by 31, turning into 281/256/176/266/176/216.
Since you have a limited EV spread of 252 SpAtk, 252 Spd and 4 HP (the last 2 don't count), we'll just say that 252 EVs increase your sat by 63, and 4 EVs increase your stat by 1. Now, your stats would be 282/256/176/329/176/279.
Finally, we will calculate natures. Natures boost one stat by 10% while lowering another by 10%, or don't touch the stats at all. Since you have a Timid nature that raises Speed and lowers Attack, Speed will go up by 10% and Attack will go down by 10%, making your final stat distribution: