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Finding the Fourth Proportional to 423.20, 629.80 and 418.88

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Solution

The fourth proportional to 423.20, 629.80 and 418.88 is: 623.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    423.20 : 629.80 = 418.88 : x
  2. Step 2: Convert to fraction form
    423.20/629.80 = 418.88/x
  3. Step 3: Cross multiply
    423.20x = 629.80 × 418.88
  4. Step 4: Simplify right side
    423.20x = 263,810.62
  5. Step 5: Solve for x
    x = 263,810.62/423.20
  6. Step 6: Final answer
    x = 623.37

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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.