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Finding the Fourth Proportional to 861.98, 1,292.81 and 423.05

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Solution

The fourth proportional to 861.98, 1,292.81 and 423.05 is: 634.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.98 : 1,292.81 = 423.05 : x
  2. Step 2: Convert to fraction form
    861.98/1,292.81 = 423.05/x
  3. Step 3: Cross multiply
    861.98x = 1,292.81 × 423.05
  4. Step 4: Simplify right side
    861.98x = 546,914.69
  5. Step 5: Solve for x
    x = 546,914.69/861.98
  6. Step 6: Final answer
    x = 634.48

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.