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Finding the Fourth Proportional to 138.41, 207.75 and 66.32

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Solution

The fourth proportional to 138.41, 207.75 and 66.32 is: 99.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.41 : 207.75 = 66.32 : x
  2. Step 2: Convert to fraction form
    138.41/207.75 = 66.32/x
  3. Step 3: Cross multiply
    138.41x = 207.75 × 66.32
  4. Step 4: Simplify right side
    138.41x = 13,776.94
  5. Step 5: Solve for x
    x = 13,776.94/138.41
  6. Step 6: Final answer
    x = 99.54

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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.