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Finding the Fourth Proportional to 138.67, 207.69 and 84.45

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Solution

The fourth proportional to 138.67, 207.69 and 84.45 is: 126.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.67 : 207.69 = 84.45 : x
  2. Step 2: Convert to fraction form
    138.67/207.69 = 84.45/x
  3. Step 3: Cross multiply
    138.67x = 207.69 × 84.45
  4. Step 4: Simplify right side
    138.67x = 17,538.38
  5. Step 5: Solve for x
    x = 17,538.38/138.67
  6. Step 6: Final answer
    x = 126.48

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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.