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Finding the Fourth Proportional to 1,279.72, 1,919.62 and 499.90

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Solution

The fourth proportional to 1,279.72, 1,919.62 and 499.90 is: 749.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,279.72 : 1,919.62 = 499.90 : x
  2. Step 2: Convert to fraction form
    1,279.72/1,919.62 = 499.90/x
  3. Step 3: Cross multiply
    1,279.72x = 1,919.62 × 499.90
  4. Step 4: Simplify right side
    1,279.72x = 959,618.04
  5. Step 5: Solve for x
    x = 959,618.04/1,279.72
  6. Step 6: Final answer
    x = 749.87

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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.