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Finding the Fourth Proportional to 522.78, 721.41 and 289.90

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Solution

The fourth proportional to 522.78, 721.41 and 289.90 is: 400.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    522.78 : 721.41 = 289.90 : x
  2. Step 2: Convert to fraction form
    522.78/721.41 = 289.90/x
  3. Step 3: Cross multiply
    522.78x = 721.41 × 289.90
  4. Step 4: Simplify right side
    522.78x = 209,136.76
  5. Step 5: Solve for x
    x = 209,136.76/522.78
  6. Step 6: Final answer
    x = 400.05

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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.