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Finding the Fourth Proportional to 20.65, 30.95 and 8.62

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Solution

The fourth proportional to 20.65, 30.95 and 8.62 is: 12.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    20.65 : 30.95 = 8.62 : x
  2. Step 2: Convert to fraction form
    20.65/30.95 = 8.62/x
  3. Step 3: Cross multiply
    20.65x = 30.95 × 8.62
  4. Step 4: Simplify right side
    20.65x = 266.59
  5. Step 5: Solve for x
    x = 266.59/20.65
  6. Step 6: Final answer
    x = 12.91

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.