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Finding the Fourth Proportional to 69.20, 103.68 and 47.80

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Solution

The fourth proportional to 69.20, 103.68 and 47.80 is: 71.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.20 : 103.68 = 47.80 : x
  2. Step 2: Convert to fraction form
    69.20/103.68 = 47.80/x
  3. Step 3: Cross multiply
    69.20x = 103.68 × 47.80
  4. Step 4: Simplify right side
    69.20x = 4,955.90
  5. Step 5: Solve for x
    x = 4,955.90/69.20
  6. Step 6: Final answer
    x = 71.62

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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.