Researchers usually start their investigation by examining some of the rich variety of low-cost and readily available data, then collect data if the needed data don't existing or are dated, inaccurate, incomplete or unreliable. a) primary; secondaryb) secondary; primaryc) primary; econometricd) secondary; econometrice) exploratory; econometric

B) secondary; primary

Explanation:

Secondary data is data collected from other researches. In this age, there is a lot of easily accessible data made available freely or at low cost. Examining them first not only help researchers find needed data cheaply, but also give them ideas about what they could find out from those data (serendipitous discovery).

Primary data is data collected from first-handed sources by the the researchers themselves by methods including surveys, interviews, direct observation, etc. It is costly to obtain so researchers only come to that when they can't find good secondary data for their purposes.

answer; a large down payment,a longer term loan, would result in a lower monthly payment;

answer; bootstrapping is your answer;