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Finding the Fourth Proportional to 428.01, 641.67 and 403.86

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Solution

The fourth proportional to 428.01, 641.67 and 403.86 is: 605.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.01 : 641.67 = 403.86 : x
  2. Step 2: Convert to fraction form
    428.01/641.67 = 403.86/x
  3. Step 3: Cross multiply
    428.01x = 641.67 × 403.86
  4. Step 4: Simplify right side
    428.01x = 259,146.21
  5. Step 5: Solve for x
    x = 259,146.21/428.01
  6. Step 6: Final answer
    x = 605.47

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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.