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Finding the Fourth Proportional to 354.92, 489.64 and 285.15

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Solution

The fourth proportional to 354.92, 489.64 and 285.15 is: 393.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    354.92 : 489.64 = 285.15 : x
  2. Step 2: Convert to fraction form
    354.92/489.64 = 285.15/x
  3. Step 3: Cross multiply
    354.92x = 489.64 × 285.15
  4. Step 4: Simplify right side
    354.92x = 139,620.85
  5. Step 5: Solve for x
    x = 139,620.85/354.92
  6. Step 6: Final answer
    x = 393.39

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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.