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Finding the Fourth Proportional to 138.96, 207.12 and 138.48

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Solution

The fourth proportional to 138.96, 207.12 and 138.48 is: 206.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.96 : 207.12 = 138.48 : x
  2. Step 2: Convert to fraction form
    138.96/207.12 = 138.48/x
  3. Step 3: Cross multiply
    138.96x = 207.12 × 138.48
  4. Step 4: Simplify right side
    138.96x = 28,681.98
  5. Step 5: Solve for x
    x = 28,681.98/138.96
  6. Step 6: Final answer
    x = 206.40

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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.