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Finding the Fourth Proportional to 5.12, 7.69 and 3.12

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Solution

The fourth proportional to 5.12, 7.69 and 3.12 is: 4.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    5.12 : 7.69 = 3.12 : x
  2. Step 2: Convert to fraction form
    5.12/7.69 = 3.12/x
  3. Step 3: Cross multiply
    5.12x = 7.69 × 3.12
  4. Step 4: Simplify right side
    5.12x = 23.99
  5. Step 5: Solve for x
    x = 23.99/5.12
  6. Step 6: Final answer
    x = 4.68

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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.