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Finding the Fourth Proportional to 71.26, 106.87 and 19.90

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Solution

The fourth proportional to 71.26, 106.87 and 19.90 is: 29.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.26 : 106.87 = 19.90 : x
  2. Step 2: Convert to fraction form
    71.26/106.87 = 19.90/x
  3. Step 3: Cross multiply
    71.26x = 106.87 × 19.90
  4. Step 4: Simplify right side
    71.26x = 2,126.71
  5. Step 5: Solve for x
    x = 2,126.71/71.26
  6. Step 6: Final answer
    x = 29.84

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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.