How do economics measure a nations standard of living

What values of data might affect the statistical measures of spread and center

Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?

Which expression will have the same sum as 3_8 + 1/4?