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Finding the Third Proportional to 77.50 and 121.25

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Solution

The third proportional to 77.50 and 121.25 is: 189.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.50 : 121.25 = 121.25 : x
  2. Step 2: Convert to fraction form
    77.50/121.25 = 121.25/x
  3. Step 3: Cross multiply
    77.50x = 121.25 × 121.25
  4. Step 4: Simplify right side
    77.50x = 14,701.56
  5. Step 5: Solve for x
    x = 14,701.56/77.50
  6. Step 6: Final answer
    x = 189.70

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Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.