Order of reaction with respect to I^- and S2O8^2-?

Woopydalan

What is the reaction order supposed to be for this reaction of each one? I got 1 for I- and 2 for S2O8, but I think it should be 1 for both of them. Can anyone confirm?? These were the numbers I found experimentally

The reason for concern here is that I did a ratio because I used twice as much s2o8 for reaction 1, then twice as much for 2, etc. The ratio should be r1/r2 = 2^x, r2/r3 = 2^x, etc. The problem is that r1/r2 gave x=3.8, when the other two gave 1.6 and 1.2, and we are supposed to find the average to get the reaction order. The average rounds off to 2, but that is because of the major outlier of 3.8. I checked and to find R you use 6.3x10^-4 / time of reaction to get the R's. I looked at the class data and everyone got the same reaction times as me, so either we all got it wrong or it is a 2nd order reaction.

The I- gave 0.8, 1.2, and 1.0 which gave a nice y=1 for the average, so its a first order. There is no cause for alarm because they are all close to each other. Would I use the same number for the s2o8 as i-, the 6.3x10^-4/time? that number came from the formula