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Finding the Fourth Proportional to 613.20, 918.60 and 418.80

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Solution

The fourth proportional to 613.20, 918.60 and 418.80 is: 627.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.20 : 918.60 = 418.80 : x
  2. Step 2: Convert to fraction form
    613.20/918.60 = 418.80/x
  3. Step 3: Cross multiply
    613.20x = 918.60 × 418.80
  4. Step 4: Simplify right side
    613.20x = 384,709.68
  5. Step 5: Solve for x
    x = 384,709.68/613.20
  6. Step 6: Final answer
    x = 627.38

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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.