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Finding the Fourth Proportional to 128.92, 193.46 and 71.18

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Solution

The fourth proportional to 128.92, 193.46 and 71.18 is: 106.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.92 : 193.46 = 71.18 : x
  2. Step 2: Convert to fraction form
    128.92/193.46 = 71.18/x
  3. Step 3: Cross multiply
    128.92x = 193.46 × 71.18
  4. Step 4: Simplify right side
    128.92x = 13,771.14
  5. Step 5: Solve for x
    x = 13,771.14/128.92
  6. Step 6: Final answer
    x = 106.82

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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.