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Finding the Fourth Proportional to 155.08, 231.42 and 138.65

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Solution

The fourth proportional to 155.08, 231.42 and 138.65 is: 206.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.08 : 231.42 = 138.65 : x
  2. Step 2: Convert to fraction form
    155.08/231.42 = 138.65/x
  3. Step 3: Cross multiply
    155.08x = 231.42 × 138.65
  4. Step 4: Simplify right side
    155.08x = 32,086.38
  5. Step 5: Solve for x
    x = 32,086.38/155.08
  6. Step 6: Final answer
    x = 206.90

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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.