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Finding the Fourth Proportional to 212.06, 318.09 and 67.78

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Solution

The fourth proportional to 212.06, 318.09 and 67.78 is: 101.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.06 : 318.09 = 67.78 : x
  2. Step 2: Convert to fraction form
    212.06/318.09 = 67.78/x
  3. Step 3: Cross multiply
    212.06x = 318.09 × 67.78
  4. Step 4: Simplify right side
    212.06x = 21,560.14
  5. Step 5: Solve for x
    x = 21,560.14/212.06
  6. Step 6: Final answer
    x = 101.67

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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.