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Finding the Fourth Proportional to 69.88, 104.87 and 31.39

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Solution

The fourth proportional to 69.88, 104.87 and 31.39 is: 47.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.88 : 104.87 = 31.39 : x
  2. Step 2: Convert to fraction form
    69.88/104.87 = 31.39/x
  3. Step 3: Cross multiply
    69.88x = 104.87 × 31.39
  4. Step 4: Simplify right side
    69.88x = 3,291.19
  5. Step 5: Solve for x
    x = 3,291.19/69.88
  6. Step 6: Final answer
    x = 47.10

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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.