Question

four numbers a b c and d are said to be in proportion of product of mean
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Answer 1

Answer:

Each quantity in a proportion is called its term or its proportional. ... If four numbers a, b, c and d are in proportional (i.e., a : b : : c : d), then a and d are known as extreme terms and b and c are called middle terms. (v) The fourth term of a proportion is called fourth proportional.