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Finding the Fourth Proportional to 861.52, 1,289.28 and 677.40

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Solution

The fourth proportional to 861.52, 1,289.28 and 677.40 is: 1,013.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.52 : 1,289.28 = 677.40 : x
  2. Step 2: Convert to fraction form
    861.52/1,289.28 = 677.40/x
  3. Step 3: Cross multiply
    861.52x = 1,289.28 × 677.40
  4. Step 4: Simplify right side
    861.52x = 873,358.27
  5. Step 5: Solve for x
    x = 873,358.27/861.52
  6. Step 6: Final answer
    x = 1,013.74

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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.