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Finding the Fourth Proportional to 428.07, 641.91 and 196.91

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Solution

The fourth proportional to 428.07, 641.91 and 196.91 is: 295.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.07 : 641.91 = 196.91 : x
  2. Step 2: Convert to fraction form
    428.07/641.91 = 196.91/x
  3. Step 3: Cross multiply
    428.07x = 641.91 × 196.91
  4. Step 4: Simplify right side
    428.07x = 126,395.29
  5. Step 5: Solve for x
    x = 126,395.29/428.07
  6. Step 6: Final answer
    x = 295.27

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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.