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Finding the Fourth Proportional to 522.78, 721.38 and 289.86

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Solution

The fourth proportional to 522.78, 721.38 and 289.86 is: 399.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    522.78 : 721.38 = 289.86 : x
  2. Step 2: Convert to fraction form
    522.78/721.38 = 289.86/x
  3. Step 3: Cross multiply
    522.78x = 721.38 × 289.86
  4. Step 4: Simplify right side
    522.78x = 209,099.21
  5. Step 5: Solve for x
    x = 209,099.21/522.78
  6. Step 6: Final answer
    x = 399.98

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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.