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Finding the Fourth Proportional to 427.46, 640.64 and 221.62

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Solution

The fourth proportional to 427.46, 640.64 and 221.62 is: 332.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.46 : 640.64 = 221.62 : x
  2. Step 2: Convert to fraction form
    427.46/640.64 = 221.62/x
  3. Step 3: Cross multiply
    427.46x = 640.64 × 221.62
  4. Step 4: Simplify right side
    427.46x = 141,978.64
  5. Step 5: Solve for x
    x = 141,978.64/427.46
  6. Step 6: Final answer
    x = 332.14

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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.