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Finding the Third Proportional to 31.50 and 69.75

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Solution

The third proportional to 31.50 and 69.75 is: 154.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.50 : 69.75 = 69.75 : x
  2. Step 2: Convert to fraction form
    31.50/69.75 = 69.75/x
  3. Step 3: Cross multiply
    31.50x = 69.75 × 69.75
  4. Step 4: Simplify right side
    31.50x = 4,865.06
  5. Step 5: Solve for x
    x = 4,865.06/31.50
  6. Step 6: Final answer
    x = 154.45

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Why These Related Problems?

These problems maintain the same ratio (2.21) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.