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Finding the Fourth Proportional to 428.04, 645.39 and 392.04

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Solution

The fourth proportional to 428.04, 645.39 and 392.04 is: 591.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.04 : 645.39 = 392.04 : x
  2. Step 2: Convert to fraction form
    428.04/645.39 = 392.04/x
  3. Step 3: Cross multiply
    428.04x = 645.39 × 392.04
  4. Step 4: Simplify right side
    428.04x = 253,018.70
  5. Step 5: Solve for x
    x = 253,018.70/428.04
  6. Step 6: Final answer
    x = 591.11

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.