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Finding the Fourth Proportional to 128.69, 191.64 and 125.49

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Solution

The fourth proportional to 128.69, 191.64 and 125.49 is: 186.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.69 : 191.64 = 125.49 : x
  2. Step 2: Convert to fraction form
    128.69/191.64 = 125.49/x
  3. Step 3: Cross multiply
    128.69x = 191.64 × 125.49
  4. Step 4: Simplify right side
    128.69x = 24,048.90
  5. Step 5: Solve for x
    x = 24,048.90/128.69
  6. Step 6: Final answer
    x = 186.88

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.