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Finding the Fourth Proportional to 68.99, 103.49 and 20.89

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Solution

The fourth proportional to 68.99, 103.49 and 20.89 is: 31.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.99 : 103.49 = 20.89 : x
  2. Step 2: Convert to fraction form
    68.99/103.49 = 20.89/x
  3. Step 3: Cross multiply
    68.99x = 103.49 × 20.89
  4. Step 4: Simplify right side
    68.99x = 2,161.28
  5. Step 5: Solve for x
    x = 2,161.28/68.99
  6. Step 6: Final answer
    x = 31.33

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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.