Suppose the price of corn rises from $30 in january to $32 in february to $32.7 in march. what is the march inflation rate

The inflation rate formula is ( CPI2 - CPI1 )
                                              x100
                                                    CPI1
CPI2 = Price of the latter date
CPI1 = Price of the earlier date

So the latter price is $32.7 and the earlier is $32 (I'm assuming you mean the inflation from January to February)

Then plug in the numbers ( 32.7 - 32 )
                                          x100
                                                 32
32.7 - 32 = .7/32 = .021875 x 100 = 2.1875

Which means the answer would be if you round 2.2%