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Finding the Third Proportional to 128.50 and 149.75

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Solution

The third proportional to 128.50 and 149.75 is: 174.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.50 : 149.75 = 149.75 : x
  2. Step 2: Convert to fraction form
    128.50/149.75 = 149.75/x
  3. Step 3: Cross multiply
    128.50x = 149.75 × 149.75
  4. Step 4: Simplify right side
    128.50x = 22,425.06
  5. Step 5: Solve for x
    x = 22,425.06/128.50
  6. Step 6: Final answer
    x = 174.51

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Why These Related Problems?

These problems maintain the same ratio (1.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.