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Finding the Fourth Proportional to 427.60, 640.82 and 221.75

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Solution

The fourth proportional to 427.60, 640.82 and 221.75 is: 332.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.60 : 640.82 = 221.75 : x
  2. Step 2: Convert to fraction form
    427.60/640.82 = 221.75/x
  3. Step 3: Cross multiply
    427.60x = 640.82 × 221.75
  4. Step 4: Simplify right side
    427.60x = 142,101.84
  5. Step 5: Solve for x
    x = 142,101.84/427.60
  6. Step 6: Final answer
    x = 332.32

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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.