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Finding the Fourth Proportional to 427.85, 641.78 and 103.22

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Solution

The fourth proportional to 427.85, 641.78 and 103.22 is: 154.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.85 : 641.78 = 103.22 : x
  2. Step 2: Convert to fraction form
    427.85/641.78 = 103.22/x
  3. Step 3: Cross multiply
    427.85x = 641.78 × 103.22
  4. Step 4: Simplify right side
    427.85x = 66,243.60
  5. Step 5: Solve for x
    x = 66,243.60/427.85
  6. Step 6: Final answer
    x = 154.83

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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.