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Finding the Third Proportional to 67.50 and 77.81

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Solution

The third proportional to 67.50 and 77.81 is: 89.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.50 : 77.81 = 77.81 : x
  2. Step 2: Convert to fraction form
    67.50/77.81 = 77.81/x
  3. Step 3: Cross multiply
    67.50x = 77.81 × 77.81
  4. Step 4: Simplify right side
    67.50x = 6,054.79
  5. Step 5: Solve for x
    x = 6,054.79/67.50
  6. Step 6: Final answer
    x = 89.70

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Why These Related Problems?

These problems maintain the same ratio (1.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.