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Finding the Fourth Proportional to 649.61, 974.58 and 418.78

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Solution

The fourth proportional to 649.61, 974.58 and 418.78 is: 628.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.61 : 974.58 = 418.78 : x
  2. Step 2: Convert to fraction form
    649.61/974.58 = 418.78/x
  3. Step 3: Cross multiply
    649.61x = 974.58 × 418.78
  4. Step 4: Simplify right side
    649.61x = 408,131.82
  5. Step 5: Solve for x
    x = 408,131.82/649.61
  6. Step 6: Final answer
    x = 628.27

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.