What do your text materials say about Texas in World War II? That's where you should start to answer this question.
For other perspectives, try reading some of these articles:
http://www.bing.com/search?q=world+war+ii+and+the+economy+of+texas&form=EDGNTC&qs=PF&cvid=dd30191437f040b0b3047c4ae13b8d35&pq=world%20war%20ii%20and%20the%20economy%20of%20texas
How did World War II improve the economy of Texas?
2 answers
"Improve" is a loaded word. The big changes during WWII were industrialization along the coast, with petrochemical industries, and the aircraft manufacturing facilities in the N Texas area, and the great move of population form rural to cities during the war.