Use the e/z notation when specifying stereochemistry remembering to use parentheses and a dash. reminder - the double bond takes precedence over alkyl groups when numbering the parent. (e)-5-bromo-5-ethylhept-2-ene when combined with naoch2ch3.

(E)-5-ethylhepta-2,4-diene

Explanation:

The  (E)-5-bromo-5-ethylhept-2-ene will undergo an E2 reaction. The ethoxide (⁻OCH₂CH₃) will deprotonate at the allylic position so that a conjugated diene results, which is more stable than a non-conjugated diene.

The stereochemistry in the name of the final product is indicated for only one double bond since the other has two identical groups on it.

there are two significant figures.