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Finding the Fourth Proportional to 345.87, 518.32 and 285.72

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Solution

The fourth proportional to 345.87, 518.32 and 285.72 is: 428.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    345.87 : 518.32 = 285.72 : x
  2. Step 2: Convert to fraction form
    345.87/518.32 = 285.72/x
  3. Step 3: Cross multiply
    345.87x = 518.32 × 285.72
  4. Step 4: Simplify right side
    345.87x = 148,092.96
  5. Step 5: Solve for x
    x = 148,092.96/345.87
  6. Step 6: Final answer
    x = 428.18

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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.