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Finding the Fourth Proportional to 439.90, 656.33 and 394.78

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Solution

The fourth proportional to 439.90, 656.33 and 394.78 is: 589.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.90 : 656.33 = 394.78 : x
  2. Step 2: Convert to fraction form
    439.90/656.33 = 394.78/x
  3. Step 3: Cross multiply
    439.90x = 656.33 × 394.78
  4. Step 4: Simplify right side
    439.90x = 259,105.96
  5. Step 5: Solve for x
    x = 259,105.96/439.90
  6. Step 6: Final answer
    x = 589.01

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.