What is the geometric mean of 4 and 9?

• A. $\sqrt{4+9}$
• B. $6$
• C. $\frac{4+9}{2}$
• D. $4-9$

Answer: (B)

Verified step by step guidance

1. Understand that the geometric mean of two numbers is the square root of their product, not the square root of their sum. The formula for the geometric mean of two numbers \(a\) and \(b\) is given by: \[ \\text{Geometric Mean} = \\sqrt{a \\times b} \]
2. Identify the two numbers given in the problem: 4 and 9.
3. Calculate the product of the two numbers: \[ 4 \\times 9 \]
4. Take the square root of the product calculated in the previous step: \[ \\sqrt{4 \\times 9} \]
5. Simplify the square root to find the geometric mean.