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Finding the Fourth Proportional to 519.78, 779.64 and 291.78

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Solution

The fourth proportional to 519.78, 779.64 and 291.78 is: 437.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    519.78 : 779.64 = 291.78 : x
  2. Step 2: Convert to fraction form
    519.78/779.64 = 291.78/x
  3. Step 3: Cross multiply
    519.78x = 779.64 × 291.78
  4. Step 4: Simplify right side
    519.78x = 227,483.36
  5. Step 5: Solve for x
    x = 227,483.36/519.78
  6. Step 6: Final answer
    x = 437.65

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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.