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Finding the Third Proportional to 478.31 and 688.13

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Solution

The third proportional to 478.31 and 688.13 is: 989.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.31 : 688.13 = 688.13 : x
  2. Step 2: Convert to fraction form
    478.31/688.13 = 688.13/x
  3. Step 3: Cross multiply
    478.31x = 688.13 × 688.13
  4. Step 4: Simplify right side
    478.31x = 473,516.02
  5. Step 5: Solve for x
    x = 473,516.02/478.31
  6. Step 6: Final answer
    x = 989.97

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Why These Related Problems?

These problems maintain the same ratio (1.44) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.