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Finding the Fourth Proportional to 419.78, 626.18 and 408.85

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Solution

The fourth proportional to 419.78, 626.18 and 408.85 is: 609.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.78 : 626.18 = 408.85 : x
  2. Step 2: Convert to fraction form
    419.78/626.18 = 408.85/x
  3. Step 3: Cross multiply
    419.78x = 626.18 × 408.85
  4. Step 4: Simplify right side
    419.78x = 256,012.38
  5. Step 5: Solve for x
    x = 256,012.38/419.78
  6. Step 6: Final answer
    x = 609.87

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.