Answer
The IUPAC name of the alkene is $(E)-4−ethylhept−3−ene$
Work Step by Step
The compound has 7 carbon atoms in its longest carbon chain containing the double bond ($hept−$). It has an $ethyl−$ substituent at position 4, and a double bond at position 3. The double bond is of $E$ stereo isomerism. So, the IUPAC name of the alkene is $(E)-4−ethylhept−3−ene$