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Finding the Third Proportional to 69 and 121.50

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Solution

The third proportional to 69 and 121.50 is: 213.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    69 : 121.50 = 121.50 : x
  2. Step 2: Convert to fraction form
    69/121.50 = 121.50/x
  3. Step 3: Cross multiply
    69x = 121.50 × 121.50
  4. Step 4: Simplify right side
    69x = 14,762.25
  5. Step 5: Solve for x
    x = 14,762.25/69
  6. Step 6: Final answer
    x = 213.95

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Why These Related Problems?

These problems maintain the same ratio (1.76) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.