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Finding the Fourth Proportional to 136.83, 189.71 and 128.55

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Solution

The fourth proportional to 136.83, 189.71 and 128.55 is: 178.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.83 : 189.71 = 128.55 : x
  2. Step 2: Convert to fraction form
    136.83/189.71 = 128.55/x
  3. Step 3: Cross multiply
    136.83x = 189.71 × 128.55
  4. Step 4: Simplify right side
    136.83x = 24,386.58
  5. Step 5: Solve for x
    x = 24,386.58/136.83
  6. Step 6: Final answer
    x = 178.23

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.