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Finding the Fourth Proportional to 128.73, 192.98 and 56.55

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Solution

The fourth proportional to 128.73, 192.98 and 56.55 is: 84.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.73 : 192.98 = 56.55 : x
  2. Step 2: Convert to fraction form
    128.73/192.98 = 56.55/x
  3. Step 3: Cross multiply
    128.73x = 192.98 × 56.55
  4. Step 4: Simplify right side
    128.73x = 10,912.74
  5. Step 5: Solve for x
    x = 10,912.74/128.73
  6. Step 6: Final answer
    x = 84.77

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.