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Finding the Third Proportional to 399.09 and 680.06

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Solution

The third proportional to 399.09 and 680.06 is: 1,158.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.09 : 680.06 = 680.06 : x
  2. Step 2: Convert to fraction form
    399.09/680.06 = 680.06/x
  3. Step 3: Cross multiply
    399.09x = 680.06 × 680.06
  4. Step 4: Simplify right side
    399.09x = 462,485.00
  5. Step 5: Solve for x
    x = 462,485.00/399.09
  6. Step 6: Final answer
    x = 1,158.84

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Why These Related Problems?

These problems maintain the same ratio (1.70) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.