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Finding the Fourth Proportional to 138.49, 206.80 and 131.47

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Solution

The fourth proportional to 138.49, 206.80 and 131.47 is: 196.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.49 : 206.80 = 131.47 : x
  2. Step 2: Convert to fraction form
    138.49/206.80 = 131.47/x
  3. Step 3: Cross multiply
    138.49x = 206.80 × 131.47
  4. Step 4: Simplify right side
    138.49x = 27,186.96
  5. Step 5: Solve for x
    x = 27,186.96/138.49
  6. Step 6: Final answer
    x = 196.32

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.