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Finding the Fourth Proportional to 354.47, 489.18 and 207.21

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Solution

The fourth proportional to 354.47, 489.18 and 207.21 is: 285.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    354.47 : 489.18 = 207.21 : x
  2. Step 2: Convert to fraction form
    354.47/489.18 = 207.21/x
  3. Step 3: Cross multiply
    354.47x = 489.18 × 207.21
  4. Step 4: Simplify right side
    354.47x = 101,362.99
  5. Step 5: Solve for x
    x = 101,362.99/354.47
  6. Step 6: Final answer
    x = 285.96

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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.