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Finding the Fourth Proportional to 1,279.89, 1,767.11 and 860.87

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Solution

The fourth proportional to 1,279.89, 1,767.11 and 860.87 is: 1,188.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.89 : 1,767.11 = 860.87 : x
  2. Step 2: Convert to fraction form
    1,279.89/1,767.11 = 860.87/x
  3. Step 3: Cross multiply
    1,279.89x = 1,767.11 × 860.87
  4. Step 4: Simplify right side
    1,279.89x = 1,521,251.99
  5. Step 5: Solve for x
    x = 1,521,251.99/1,279.89
  6. Step 6: Final answer
    x = 1,188.58

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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.