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Finding the Fourth Proportional to 137.13, 205.57 and 78.65

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Solution

The fourth proportional to 137.13, 205.57 and 78.65 is: 117.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.13 : 205.57 = 78.65 : x
  2. Step 2: Convert to fraction form
    137.13/205.57 = 78.65/x
  3. Step 3: Cross multiply
    137.13x = 205.57 × 78.65
  4. Step 4: Simplify right side
    137.13x = 16,168.40
  5. Step 5: Solve for x
    x = 16,168.40/137.13
  6. Step 6: Final answer
    x = 117.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.