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Finding the Fourth Proportional to 128.69, 193.12 and 56.56

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Solution

The fourth proportional to 128.69, 193.12 and 56.56 is: 84.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.69 : 193.12 = 56.56 : x
  2. Step 2: Convert to fraction form
    128.69/193.12 = 56.56/x
  3. Step 3: Cross multiply
    128.69x = 193.12 × 56.56
  4. Step 4: Simplify right side
    128.69x = 10,922.24
  5. Step 5: Solve for x
    x = 10,922.24/128.69
  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.