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Finding the Third Proportional to 309.15 and 680.77

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Solution

The third proportional to 309.15 and 680.77 is: 1,499.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.15 : 680.77 = 680.77 : x
  2. Step 2: Convert to fraction form
    309.15/680.77 = 680.77/x
  3. Step 3: Cross multiply
    309.15x = 680.77 × 680.77
  4. Step 4: Simplify right side
    309.15x = 463,444.83
  5. Step 5: Solve for x
    x = 463,444.83/309.15
  6. Step 6: Final answer
    x = 1,499.10

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Why These Related Problems?

These problems maintain the same ratio (2.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.