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Finding the Fourth Proportional to 71.25, 106.87 and 19.89

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Solution

The fourth proportional to 71.25, 106.87 and 19.89 is: 29.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.25 : 106.87 = 19.89 : x
  2. Step 2: Convert to fraction form
    71.25/106.87 = 19.89/x
  3. Step 3: Cross multiply
    71.25x = 106.87 × 19.89
  4. Step 4: Simplify right side
    71.25x = 2,125.01
  5. Step 5: Solve for x
    x = 2,125.01/71.25
  6. Step 6: Final answer
    x = 29.83

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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.