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Finding the Fourth Proportional to 427.87, 640.99 and 210.79

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Solution

The fourth proportional to 427.87, 640.99 and 210.79 is: 315.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.87 : 640.99 = 210.79 : x
  2. Step 2: Convert to fraction form
    427.87/640.99 = 210.79/x
  3. Step 3: Cross multiply
    427.87x = 640.99 × 210.79
  4. Step 4: Simplify right side
    427.87x = 135,114.28
  5. Step 5: Solve for x
    x = 135,114.28/427.87
  6. Step 6: Final answer
    x = 315.78

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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.