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Finding the Fourth Proportional to 645, 889.20 and 423.87

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Solution

The fourth proportional to 645, 889.20 and 423.87 is: 584.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    645 : 889.20 = 423.87 : x
  2. Step 2: Convert to fraction form
    645/889.20 = 423.87/x
  3. Step 3: Cross multiply
    645x = 889.20 × 423.87
  4. Step 4: Simplify right side
    645x = 376,905.20
  5. Step 5: Solve for x
    x = 376,905.20/645
  6. Step 6: Final answer
    x = 584.35

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.