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Finding the Fourth Proportional to 856.91, 1,284.59 and 308.70

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Solution

The fourth proportional to 856.91, 1,284.59 and 308.70 is: 462.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.91 : 1,284.59 = 308.70 : x
  2. Step 2: Convert to fraction form
    856.91/1,284.59 = 308.70/x
  3. Step 3: Cross multiply
    856.91x = 1,284.59 × 308.70
  4. Step 4: Simplify right side
    856.91x = 396,556.21
  5. Step 5: Solve for x
    x = 396,556.21/856.91
  6. Step 6: Final answer
    x = 462.78

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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.