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Finding the Fourth Proportional to 658.78, 909.18 and 396.80

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Solution

The fourth proportional to 658.78, 909.18 and 396.80 is: 547.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    658.78 : 909.18 = 396.80 : x
  2. Step 2: Convert to fraction form
    658.78/909.18 = 396.80/x
  3. Step 3: Cross multiply
    658.78x = 909.18 × 396.80
  4. Step 4: Simplify right side
    658.78x = 360,762.62
  5. Step 5: Solve for x
    x = 360,762.62/658.78
  6. Step 6: Final answer
    x = 547.62

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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.