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Finding the Fourth Proportional to 138.72, 191.43 and 134.58

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Solution

The fourth proportional to 138.72, 191.43 and 134.58 is: 185.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.72 : 191.43 = 134.58 : x
  2. Step 2: Convert to fraction form
    138.72/191.43 = 134.58/x
  3. Step 3: Cross multiply
    138.72x = 191.43 × 134.58
  4. Step 4: Simplify right side
    138.72x = 25,762.65
  5. Step 5: Solve for x
    x = 25,762.65/138.72
  6. Step 6: Final answer
    x = 185.72

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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.