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Finding the Fourth Proportional to 664.38, 997.29 and 421.11

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Solution

The fourth proportional to 664.38, 997.29 and 421.11 is: 632.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.38 : 997.29 = 421.11 : x
  2. Step 2: Convert to fraction form
    664.38/997.29 = 421.11/x
  3. Step 3: Cross multiply
    664.38x = 997.29 × 421.11
  4. Step 4: Simplify right side
    664.38x = 419,968.79
  5. Step 5: Solve for x
    x = 419,968.79/664.38
  6. Step 6: Final answer
    x = 632.12

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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.