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Finding the Fourth Proportional to 212.05, 318.09 and 82.11

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Solution

The fourth proportional to 212.05, 318.09 and 82.11 is: 123.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.05 : 318.09 = 82.11 : x
  2. Step 2: Convert to fraction form
    212.05/318.09 = 82.11/x
  3. Step 3: Cross multiply
    212.05x = 318.09 × 82.11
  4. Step 4: Simplify right side
    212.05x = 26,118.37
  5. Step 5: Solve for x
    x = 26,118.37/212.05
  6. Step 6: Final answer
    x = 123.17

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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.