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Finding the Fourth Proportional to 128.71, 178.62 and 125.83

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Solution

The fourth proportional to 128.71, 178.62 and 125.83 is: 174.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.71 : 178.62 = 125.83 : x
  2. Step 2: Convert to fraction form
    128.71/178.62 = 125.83/x
  3. Step 3: Cross multiply
    128.71x = 178.62 × 125.83
  4. Step 4: Simplify right side
    128.71x = 22,475.75
  5. Step 5: Solve for x
    x = 22,475.75/128.71
  6. Step 6: Final answer
    x = 174.62

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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.