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Finding the Fourth Proportional to 619.78, 929.86 and 331

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Solution

The fourth proportional to 619.78, 929.86 and 331 is: 496.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.78 : 929.86 = 331 : x
  2. Step 2: Convert to fraction form
    619.78/929.86 = 331/x
  3. Step 3: Cross multiply
    619.78x = 929.86 × 331
  4. Step 4: Simplify right side
    619.78x = 307,783.66
  5. Step 5: Solve for x
    x = 307,783.66/619.78
  6. Step 6: Final answer
    x = 496.60

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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.