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Finding the Fourth Proportional to 136.65, 204.49 and 78.71

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Solution

The fourth proportional to 136.65, 204.49 and 78.71 is: 117.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.65 : 204.49 = 78.71 : x
  2. Step 2: Convert to fraction form
    136.65/204.49 = 78.71/x
  3. Step 3: Cross multiply
    136.65x = 204.49 × 78.71
  4. Step 4: Simplify right side
    136.65x = 16,094.48
  5. Step 5: Solve for x
    x = 16,094.48/136.65
  6. Step 6: Final answer
    x = 117.78

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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.