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Finding the Fourth Proportional to 619.78, 856.13 and 496.31

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Solution

The fourth proportional to 619.78, 856.13 and 496.31 is: 685.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.78 : 856.13 = 496.31 : x
  2. Step 2: Convert to fraction form
    619.78/856.13 = 496.31/x
  3. Step 3: Cross multiply
    619.78x = 856.13 × 496.31
  4. Step 4: Simplify right side
    619.78x = 424,905.54
  5. Step 5: Solve for x
    x = 424,905.54/619.78
  6. Step 6: Final answer
    x = 685.58

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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.