This individual is the presiding officer of the senate whenever the vice president is not present: speaker of the house chief justice secretary of state president pro tempore

The answer is president pro tempore.  This refers to the second-ranking officer in the Senate who takes over if the Vice President is absent.  Though limited, the president pro tempore does some of the functions of the Vice President during meetings.  Other functions are appointing committees and officials and receive Senate reports. Apart from that, he can tell the President to have Congress summon back for sessions.

using the scientific method.

i believe the answer is: returns on investments, no wages

people who belong in upper class society would most likely get there by obtaining multiple source of income, which a certain percentage of ownership for businesses. since most of them are job creator, they would most likely get their money from profit, not wages.