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Finding the Fourth Proportional to 212.20, 318.38 and 109.42

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Solution

The fourth proportional to 212.20, 318.38 and 109.42 is: 164.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.20 : 318.38 = 109.42 : x
  2. Step 2: Convert to fraction form
    212.20/318.38 = 109.42/x
  3. Step 3: Cross multiply
    212.20x = 318.38 × 109.42
  4. Step 4: Simplify right side
    212.20x = 34,835.80
  5. Step 5: Solve for x
    x = 34,835.80/212.20
  6. Step 6: Final answer
    x = 164.17

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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.