[-A-] [-B-] [-C-] time reaction Rate

1) 0.069M 0.0356M 0.000862M 37s 1.16e^-5

2) 0.069M 0.0172M 0.000862M 74s 5.82e^-6

3) 0.0345M 0.0356M 0.000862M 67s 6.43e^-6

For an in class lab I have calculated to following data. Based from the data I have been able to determine that [-B-] has a reaction order of 1 due to the rate doubling when the concentration is doubled. My question is about [A]'s reaction order how would i determine it, knowing that the factor change between rates 3 and 2 is (6.43e^-6/5.82e^-6) = 1.1. Sorry for any grammar errors.

Thank you.