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Finding the Fourth Proportional to 128.72, 193.14 and 56.56

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Solution

The fourth proportional to 128.72, 193.14 and 56.56 is: 84.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.72 : 193.14 = 56.56 : x
  2. Step 2: Convert to fraction form
    128.72/193.14 = 56.56/x
  3. Step 3: Cross multiply
    128.72x = 193.14 × 56.56
  4. Step 4: Simplify right side
    128.72x = 10,924.00
  5. Step 5: Solve for x
    x = 10,924.00/128.72
  6. Step 6: Final answer
    x = 84.87

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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.