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Finding the Fourth Proportional to 639.78, 882.65 and 403.67

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Solution

The fourth proportional to 639.78, 882.65 and 403.67 is: 556.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.78 : 882.65 = 403.67 : x
  2. Step 2: Convert to fraction form
    639.78/882.65 = 403.67/x
  3. Step 3: Cross multiply
    639.78x = 882.65 × 403.67
  4. Step 4: Simplify right side
    639.78x = 356,292.89
  5. Step 5: Solve for x
    x = 356,292.89/639.78
  6. Step 6: Final answer
    x = 556.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.