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Finding the Fourth Proportional to 138.00, 207.11 and 65.91

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Solution

The fourth proportional to 138.00, 207.11 and 65.91 is: 98.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.00 : 207.11 = 65.91 : x
  2. Step 2: Convert to fraction form
    138.00/207.11 = 65.91/x
  3. Step 3: Cross multiply
    138.00x = 207.11 × 65.91
  4. Step 4: Simplify right side
    138.00x = 13,651.19
  5. Step 5: Solve for x
    x = 13,651.19/138.00
  6. Step 6: Final answer
    x = 98.92

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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.