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Finding the Fourth Proportional to 861.34, 1,290.39 and 449.86

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Solution

The fourth proportional to 861.34, 1,290.39 and 449.86 is: 673.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.34 : 1,290.39 = 449.86 : x
  2. Step 2: Convert to fraction form
    861.34/1,290.39 = 449.86/x
  3. Step 3: Cross multiply
    861.34x = 1,290.39 × 449.86
  4. Step 4: Simplify right side
    861.34x = 580,494.85
  5. Step 5: Solve for x
    x = 580,494.85/861.34
  6. Step 6: Final answer
    x = 673.94

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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.