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Finding the Fourth Proportional to 128.81, 176.71 and 126.65

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Solution

The fourth proportional to 128.81, 176.71 and 126.65 is: 173.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.81 : 176.71 = 126.65 : x
  2. Step 2: Convert to fraction form
    128.81/176.71 = 126.65/x
  3. Step 3: Cross multiply
    128.81x = 176.71 × 126.65
  4. Step 4: Simplify right side
    128.81x = 22,380.32
  5. Step 5: Solve for x
    x = 22,380.32/128.81
  6. Step 6: Final answer
    x = 173.75

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.