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Finding the Fourth Proportional to 138.98, 191.58 and 109.42

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Solution

The fourth proportional to 138.98, 191.58 and 109.42 is: 150.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.98 : 191.58 = 109.42 : x
  2. Step 2: Convert to fraction form
    138.98/191.58 = 109.42/x
  3. Step 3: Cross multiply
    138.98x = 191.58 × 109.42
  4. Step 4: Simplify right side
    138.98x = 20,962.41
  5. Step 5: Solve for x
    x = 20,962.41/138.98
  6. Step 6: Final answer
    x = 150.83

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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.