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Finding the Fourth Proportional to 856.65, 1,284.86 and 308.75

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Solution

The fourth proportional to 856.65, 1,284.86 and 308.75 is: 463.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.65 : 1,284.86 = 308.75 : x
  2. Step 2: Convert to fraction form
    856.65/1,284.86 = 308.75/x
  3. Step 3: Cross multiply
    856.65x = 1,284.86 × 308.75
  4. Step 4: Simplify right side
    856.65x = 396,692.56
  5. Step 5: Solve for x
    x = 396,692.56/856.65
  6. Step 6: Final answer
    x = 463.07

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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.