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Finding the Third Proportional to 315.56 and 686.39

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Solution

The third proportional to 315.56 and 686.39 is: 1,492.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    315.56 : 686.39 = 686.39 : x
  2. Step 2: Convert to fraction form
    315.56/686.39 = 686.39/x
  3. Step 3: Cross multiply
    315.56x = 686.39 × 686.39
  4. Step 4: Simplify right side
    315.56x = 471,132.09
  5. Step 5: Solve for x
    x = 471,132.09/315.56
  6. Step 6: Final answer
    x = 1,492.99

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Why These Related Problems?

These problems maintain the same ratio (2.18) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.