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Finding the Fourth Proportional to 856.91, 1,285.36 and 207.64

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Solution

The fourth proportional to 856.91, 1,285.36 and 207.64 is: 311.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.91 : 1,285.36 = 207.64 : x
  2. Step 2: Convert to fraction form
    856.91/1,285.36 = 207.64/x
  3. Step 3: Cross multiply
    856.91x = 1,285.36 × 207.64
  4. Step 4: Simplify right side
    856.91x = 266,893.63
  5. Step 5: Solve for x
    x = 266,893.63/856.91
  6. Step 6: Final answer
    x = 311.46

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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.