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Finding the Fourth Proportional to 856.94, 1,285.59 and 309.12

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Solution

The fourth proportional to 856.94, 1,285.59 and 309.12 is: 463.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.94 : 1,285.59 = 309.12 : x
  2. Step 2: Convert to fraction form
    856.94/1,285.59 = 309.12/x
  3. Step 3: Cross multiply
    856.94x = 1,285.59 × 309.12
  4. Step 4: Simplify right side
    856.94x = 397,401.58
  5. Step 5: Solve for x
    x = 397,401.58/856.94
  6. Step 6: Final answer
    x = 463.75

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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.