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Finding the Fourth Proportional to 579.78, 869.76 and 319.91

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Solution

The fourth proportional to 579.78, 869.76 and 319.91 is: 479.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    579.78 : 869.76 = 319.91 : x
  2. Step 2: Convert to fraction form
    579.78/869.76 = 319.91/x
  3. Step 3: Cross multiply
    579.78x = 869.76 × 319.91
  4. Step 4: Simplify right side
    579.78x = 278,240.57
  5. Step 5: Solve for x
    x = 278,240.57/579.78
  6. Step 6: Final answer
    x = 479.91

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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.