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Finding the Fourth Proportional to 428.05, 640.83 and 325.75

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Solution

The fourth proportional to 428.05, 640.83 and 325.75 is: 487.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.05 : 640.83 = 325.75 : x
  2. Step 2: Convert to fraction form
    428.05/640.83 = 325.75/x
  3. Step 3: Cross multiply
    428.05x = 640.83 × 325.75
  4. Step 4: Simplify right side
    428.05x = 208,750.37
  5. Step 5: Solve for x
    x = 208,750.37/428.05
  6. Step 6: Final answer
    x = 487.68

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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.