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Finding the Fourth Proportional to 721.77, 1,081.27 and 647.85

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Solution

The fourth proportional to 721.77, 1,081.27 and 647.85 is: 970.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.77 : 1,081.27 = 647.85 : x
  2. Step 2: Convert to fraction form
    721.77/1,081.27 = 647.85/x
  3. Step 3: Cross multiply
    721.77x = 1,081.27 × 647.85
  4. Step 4: Simplify right side
    721.77x = 700,500.77
  5. Step 5: Solve for x
    x = 700,500.77/721.77
  6. Step 6: Final answer
    x = 970.53

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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.