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Finding the Fourth Proportional to 514.72, 771.18 and 428.61

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Solution

The fourth proportional to 514.72, 771.18 and 428.61 is: 642.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    514.72 : 771.18 = 428.61 : x
  2. Step 2: Convert to fraction form
    514.72/771.18 = 428.61/x
  3. Step 3: Cross multiply
    514.72x = 771.18 × 428.61
  4. Step 4: Simplify right side
    514.72x = 330,535.46
  5. Step 5: Solve for x
    x = 330,535.46/514.72
  6. Step 6: Final answer
    x = 642.16

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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.