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Finding the Fourth Proportional to 136.68, 204.84 and 85.20

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Solution

The fourth proportional to 136.68, 204.84 and 85.20 is: 127.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.68 : 204.84 = 85.20 : x
  2. Step 2: Convert to fraction form
    136.68/204.84 = 85.20/x
  3. Step 3: Cross multiply
    136.68x = 204.84 × 85.20
  4. Step 4: Simplify right side
    136.68x = 17,452.37
  5. Step 5: Solve for x
    x = 17,452.37/136.68
  6. Step 6: Final answer
    x = 127.69

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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.