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Finding the Fourth Proportional to 676.66, 938.06 and 639.70

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Solution

The fourth proportional to 676.66, 938.06 and 639.70 is: 886.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    676.66 : 938.06 = 639.70 : x
  2. Step 2: Convert to fraction form
    676.66/938.06 = 639.70/x
  3. Step 3: Cross multiply
    676.66x = 938.06 × 639.70
  4. Step 4: Simplify right side
    676.66x = 600,076.98
  5. Step 5: Solve for x
    x = 600,076.98/676.66
  6. Step 6: Final answer
    x = 886.82

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.