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Finding the Fourth Proportional to 418.21, 621.70 and 405.92

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Solution

The fourth proportional to 418.21, 621.70 and 405.92 is: 603.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.21 : 621.70 = 405.92 : x
  2. Step 2: Convert to fraction form
    418.21/621.70 = 405.92/x
  3. Step 3: Cross multiply
    418.21x = 621.70 × 405.92
  4. Step 4: Simplify right side
    418.21x = 252,361.00
  5. Step 5: Solve for x
    x = 252,361.00/418.21
  6. Step 6: Final answer
    x = 603.43

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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.