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Finding the Fourth Proportional to 138.64, 209.26 and 138.64

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Solution

The fourth proportional to 138.64, 209.26 and 138.64 is: 209.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.64 : 209.26 = 138.64 : x
  2. Step 2: Convert to fraction form
    138.64/209.26 = 138.64/x
  3. Step 3: Cross multiply
    138.64x = 209.26 × 138.64
  4. Step 4: Simplify right side
    138.64x = 29,011.81
  5. Step 5: Solve for x
    x = 29,011.81/138.64
  6. Step 6: Final answer
    x = 209.26

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.