Final answer:
Equiano refers to the slave purchasers as having 'improvident avarice' because it combines the qualities of not thinking ahead and extreme greed for wealth.
Step-by-step explanation:
The term 'improvident avarice' is used by Equiano to describe the slave purchasers because it combines two negative qualities: 'improvident', meaning not thinking ahead or planning carefully, and 'avarice', meaning extreme greed for wealth or material gain.
Equiano is implying that the slave purchasers are driven by their insatiable desire for wealth and are willing to make impulsive decisions without considering the consequences for the enslaved people they are purchasing.
This term captures the negative characteristics of the slave purchasers and highlights the exploitative nature of the slave trade.