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Finding the Fourth Proportional to 428.87, 643.30 and 104.24

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Solution

The fourth proportional to 428.87, 643.30 and 104.24 is: 156.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.87 : 643.30 = 104.24 : x
  2. Step 2: Convert to fraction form
    428.87/643.30 = 104.24/x
  3. Step 3: Cross multiply
    428.87x = 643.30 × 104.24
  4. Step 4: Simplify right side
    428.87x = 67,059.53
  5. Step 5: Solve for x
    x = 67,059.53/428.87
  6. Step 6: Final answer
    x = 156.36

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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.