Final answer:
The main purpose of the lab is to analyze and present data on real estate sale prices and help students understand data analysis and presentation techniques.
Step-by-step explanation:
The main purpose of the 3.14 lab: input and formatted output - house real estate summary is to analyze and present the collected data on sale prices of homes recently listed in the county. The lab helps students understand how to describe and present data in different formats, such as finding the median price and the variation of prices. This helps in making informed decisions when buying a house in a particular area.