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Finding the Third Proportional to 128.50 and 140

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Solution

The third proportional to 128.50 and 140 is: 152.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.50 : 140 = 140 : x
  2. Step 2: Convert to fraction form
    128.50/140 = 140/x
  3. Step 3: Cross multiply
    128.50x = 140 × 140
  4. Step 4: Simplify right side
    128.50x = 19,600
  5. Step 5: Solve for x
    x = 19,600/128.50
  6. Step 6: Final answer
    x = 152.53

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Why These Related Problems?

These problems maintain the same ratio (1.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.