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Finding the Fourth Proportional to 138.31, 206.55 and 117.79

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Solution

The fourth proportional to 138.31, 206.55 and 117.79 is: 175.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.31 : 206.55 = 117.79 : x
  2. Step 2: Convert to fraction form
    138.31/206.55 = 117.79/x
  3. Step 3: Cross multiply
    138.31x = 206.55 × 117.79
  4. Step 4: Simplify right side
    138.31x = 24,329.01
  5. Step 5: Solve for x
    x = 24,329.01/138.31
  6. Step 6: Final answer
    x = 175.91

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.