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Finding the Fourth Proportional to 427.17, 639.95 and 221.43

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Solution

The fourth proportional to 427.17, 639.95 and 221.43 is: 331.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.17 : 639.95 = 221.43 : x
  2. Step 2: Convert to fraction form
    427.17/639.95 = 221.43/x
  3. Step 3: Cross multiply
    427.17x = 639.95 × 221.43
  4. Step 4: Simplify right side
    427.17x = 141,703.02
  5. Step 5: Solve for x
    x = 141,703.02/427.17
  6. Step 6: Final answer
    x = 331.73

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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.