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Finding the Fourth Proportional to 489.21, 730.26 and 421.17

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Solution

The fourth proportional to 489.21, 730.26 and 421.17 is: 628.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.21 : 730.26 = 421.17 : x
  2. Step 2: Convert to fraction form
    489.21/730.26 = 421.17/x
  3. Step 3: Cross multiply
    489.21x = 730.26 × 421.17
  4. Step 4: Simplify right side
    489.21x = 307,563.60
  5. Step 5: Solve for x
    x = 307,563.60/489.21
  6. Step 6: Final answer
    x = 628.69

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.