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Finding the Fourth Proportional to 128.00, 191.85 and 91.82

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Solution

The fourth proportional to 128.00, 191.85 and 91.82 is: 137.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.00 : 191.85 = 91.82 : x
  2. Step 2: Convert to fraction form
    128.00/191.85 = 91.82/x
  3. Step 3: Cross multiply
    128.00x = 191.85 × 91.82
  4. Step 4: Simplify right side
    128.00x = 17,615.24
  5. Step 5: Solve for x
    x = 17,615.24/128.00
  6. Step 6: Final answer
    x = 137.62

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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.