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Finding the Fourth Proportional to 1,279.68, 1,765.92 and 720.18

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Solution

The fourth proportional to 1,279.68, 1,765.92 and 720.18 is: 993.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.68 : 1,765.92 = 720.18 : x
  2. Step 2: Convert to fraction form
    1,279.68/1,765.92 = 720.18/x
  3. Step 3: Cross multiply
    1,279.68x = 1,765.92 × 720.18
  4. Step 4: Simplify right side
    1,279.68x = 1,271,780.27
  5. Step 5: Solve for x
    x = 1,271,780.27/1,279.68
  6. Step 6: Final answer
    x = 993.83

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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.