Figure 4.
Frequency of observations at various places on the response surface as indicated by the shaded areas. The presence of skew and multimodality are apparent in several areas of the lower response surface.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.