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Finding the Fourth Proportional to 69.21, 103.91 and 56.21

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Solution

The fourth proportional to 69.21, 103.91 and 56.21 is: 84.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.21 : 103.91 = 56.21 : x
  2. Step 2: Convert to fraction form
    69.21/103.91 = 56.21/x
  3. Step 3: Cross multiply
    69.21x = 103.91 × 56.21
  4. Step 4: Simplify right side
    69.21x = 5,839.98
  5. Step 5: Solve for x
    x = 5,839.98/69.21
  6. Step 6: Final answer
    x = 84.38

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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.