I can't get my table to line up so I've surrounded the values in curly brackets.

Experiment [SO2]i [O2]i IRD O2
{1} {0.05} {0.05} {7.3*[10^(-2)]}
{2} {0.10} {0.05} {2.9*[10^(-2)]}
{3} {0.10} {0.15} {2.6*[10^(-1)]}
{4} {0.12} {0.12} {?????????????}

so overall oreder is 4 or specifically:
rate=k([SO2]^2)([O2]^2) with k= 1168 so
rate=1168([SO2]^2)([O2]^2)

not sure what to do here I believe that rate relationship is:

-(delta [O2)]/delta time)=
1/2(delta [SO3]/delta time)

and I think I need to use trials 2&3 because that is where [SO2] is held constant.

Answer is given as 4.84*10^(-1) trying to figure out how to get there.

Thank you