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Finding the Third Proportional to 81.63 and 128.14

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Solution

The third proportional to 81.63 and 128.14 is: 201.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.63 : 128.14 = 128.14 : x
  2. Step 2: Convert to fraction form
    81.63/128.14 = 128.14/x
  3. Step 3: Cross multiply
    81.63x = 128.14 × 128.14
  4. Step 4: Simplify right side
    81.63x = 16,421.02
  5. Step 5: Solve for x
    x = 16,421.02/81.63
  6. Step 6: Final answer
    x = 201.16

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Why These Related Problems?

These problems maintain the same ratio (1.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.