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Finding the Fourth Proportional to 355.61, 489.03 and 284.78

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Solution

The fourth proportional to 355.61, 489.03 and 284.78 is: 391.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.61 : 489.03 = 284.78 : x
  2. Step 2: Convert to fraction form
    355.61/489.03 = 284.78/x
  3. Step 3: Cross multiply
    355.61x = 489.03 × 284.78
  4. Step 4: Simplify right side
    355.61x = 139,265.96
  5. Step 5: Solve for x
    x = 139,265.96/355.61
  6. Step 6: Final answer
    x = 391.63

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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.