Correct Answer:
A. (a+b)/2
The correct answer is (a+b)/2 because the standard formula for finding a single arithmetic mean (A.M.) between two values is their mathematical average.
- Step 1 (Definition): For any two numbers a and b, their single arithmetic mean forms an arithmetic progression sequence. This value sits exactly halfway between them.
- Step 2 (Formula Calculation): The midpoint formula is found by adding the two terms together and dividing the total sum by 2, which gives us
(a + b) / 2. - Incorrect Options:
- =โab is incorrect because it represents the Geometric Mean (G.M.) between two positive numbers.
- 2ab/(a+b) is incorrect because it represents the Harmonic Mean (H.M.) between two numbers.
- None of these is incorrect because the first option is the exact mathematical standard for the arithmetic mean.