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Finding the Fourth Proportional to 354.15, 489.30 and 287.13

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Solution

The fourth proportional to 354.15, 489.30 and 287.13 is: 396.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    354.15 : 489.30 = 287.13 : x
  2. Step 2: Convert to fraction form
    354.15/489.30 = 287.13/x
  3. Step 3: Cross multiply
    354.15x = 489.30 × 287.13
  4. Step 4: Simplify right side
    354.15x = 140,492.71
  5. Step 5: Solve for x
    x = 140,492.71/354.15
  6. Step 6: Final answer
    x = 396.70

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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.