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Finding the Fourth Proportional to 428.00, 641.93 and 139.44

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Solution

The fourth proportional to 428.00, 641.93 and 139.44 is: 209.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.00 : 641.93 = 139.44 : x
  2. Step 2: Convert to fraction form
    428.00/641.93 = 139.44/x
  3. Step 3: Cross multiply
    428.00x = 641.93 × 139.44
  4. Step 4: Simplify right side
    428.00x = 89,511.07
  5. Step 5: Solve for x
    x = 89,511.07/428.00
  6. Step 6: Final answer
    x = 209.14

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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.