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Finding the Fourth Proportional to 69.40, 103.86 and 45.28

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Solution

The fourth proportional to 69.40, 103.86 and 45.28 is: 67.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.40 : 103.86 = 45.28 : x
  2. Step 2: Convert to fraction form
    69.40/103.86 = 45.28/x
  3. Step 3: Cross multiply
    69.40x = 103.86 × 45.28
  4. Step 4: Simplify right side
    69.40x = 4,702.78
  5. Step 5: Solve for x
    x = 4,702.78/69.40
  6. Step 6: Final answer
    x = 67.76

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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.