For this and other similar questions, consult G. Socrates's book IR and Raman Group Frequencies:

http://b-ok.org/book/1257419/6815f9

Actually ethyl acetoacetate exhibit keto-enol tautomerism. The keto form has two carbonyl groups with separate stretching frequencies at 1733 and 1710 cm-1 in FT-IR spectra. But in enol form only one carbonyl group present and exhibit frequency at 1645 cm-1 (because intramolecular hydrogen bonding lowers the carbonyl frequency) and also C=C stretching exhibit at 1650 cm-1 in enol form because of cyclization.

1465 medium C-H bending methylene group

Frequency range for the active methylene groups between the ester and the carbonyl groups in an acetoacetate functionality is below str. band 2900-3000 cm-1(SP3 hybridized carbon) in keto form where as its enol form of it shows =C-H str. band around 3015 cm-1.