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Finding the Fourth Proportional to 856.79, 1,284.87 and 308.81

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Solution

The fourth proportional to 856.79, 1,284.87 and 308.81 is: 463.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.79 : 1,284.87 = 308.81 : x
  2. Step 2: Convert to fraction form
    856.79/1,284.87 = 308.81/x
  3. Step 3: Cross multiply
    856.79x = 1,284.87 × 308.81
  4. Step 4: Simplify right side
    856.79x = 396,780.70
  5. Step 5: Solve for x
    x = 396,780.70/856.79
  6. Step 6: Final answer
    x = 463.10

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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.