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Finding the Fourth Proportional to 159.20, 219.42 and 138.68

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Solution

The fourth proportional to 159.20, 219.42 and 138.68 is: 191.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.20 : 219.42 = 138.68 : x
  2. Step 2: Convert to fraction form
    159.20/219.42 = 138.68/x
  3. Step 3: Cross multiply
    159.20x = 219.42 × 138.68
  4. Step 4: Simplify right side
    159.20x = 30,429.17
  5. Step 5: Solve for x
    x = 30,429.17/159.20
  6. Step 6: Final answer
    x = 191.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.