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Finding the Fourth Proportional to 856.20, 1,283.72 and 439.99

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Solution

The fourth proportional to 856.20, 1,283.72 and 439.99 is: 659.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.20 : 1,283.72 = 439.99 : x
  2. Step 2: Convert to fraction form
    856.20/1,283.72 = 439.99/x
  3. Step 3: Cross multiply
    856.20x = 1,283.72 × 439.99
  4. Step 4: Simplify right side
    856.20x = 564,821.85
  5. Step 5: Solve for x
    x = 564,821.85/856.20
  6. Step 6: Final answer
    x = 659.68

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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.