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Finding the Fourth Proportional to 1,279.86, 1,765.87 and 720.29

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Solution

The fourth proportional to 1,279.86, 1,765.87 and 720.29 is: 993.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.86 : 1,765.87 = 720.29 : x
  2. Step 2: Convert to fraction form
    1,279.86/1,765.87 = 720.29/x
  3. Step 3: Cross multiply
    1,279.86x = 1,765.87 × 720.29
  4. Step 4: Simplify right side
    1,279.86x = 1,271,938.50
  5. Step 5: Solve for x
    x = 1,271,938.50/1,279.86
  6. Step 6: Final answer
    x = 993.81

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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.