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Finding the Fourth Proportional to 684.78, 945.21 and 487.98

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Solution

The fourth proportional to 684.78, 945.21 and 487.98 is: 673.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    684.78 : 945.21 = 487.98 : x
  2. Step 2: Convert to fraction form
    684.78/945.21 = 487.98/x
  3. Step 3: Cross multiply
    684.78x = 945.21 × 487.98
  4. Step 4: Simplify right side
    684.78x = 461,243.58
  5. Step 5: Solve for x
    x = 461,243.58/684.78
  6. Step 6: Final answer
    x = 673.56

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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.