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Finding the Fourth Proportional to 427.81, 641.27 and 208.11

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Solution

The fourth proportional to 427.81, 641.27 and 208.11 is: 311.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.81 : 641.27 = 208.11 : x
  2. Step 2: Convert to fraction form
    427.81/641.27 = 208.11/x
  3. Step 3: Cross multiply
    427.81x = 641.27 × 208.11
  4. Step 4: Simplify right side
    427.81x = 133,453.66
  5. Step 5: Solve for x
    x = 133,453.66/427.81
  6. Step 6: Final answer
    x = 311.95

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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.