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Finding the Fourth Proportional to 427.60, 641.33 and 139.04

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Solution

The fourth proportional to 427.60, 641.33 and 139.04 is: 208.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.60 : 641.33 = 139.04 : x
  2. Step 2: Convert to fraction form
    427.60/641.33 = 139.04/x
  3. Step 3: Cross multiply
    427.60x = 641.33 × 139.04
  4. Step 4: Simplify right side
    427.60x = 89,172.13
  5. Step 5: Solve for x
    x = 89,172.13/427.60
  6. Step 6: Final answer
    x = 208.54

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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.