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Finding the Fourth Proportional to 128.54, 191.33 and 127.85

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Solution

The fourth proportional to 128.54, 191.33 and 127.85 is: 190.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.54 : 191.33 = 127.85 : x
  2. Step 2: Convert to fraction form
    128.54/191.33 = 127.85/x
  3. Step 3: Cross multiply
    128.54x = 191.33 × 127.85
  4. Step 4: Simplify right side
    128.54x = 24,459.94
  5. Step 5: Solve for x
    x = 24,459.94/128.54
  6. Step 6: Final answer
    x = 190.30

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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.