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Finding the Fourth Proportional to 663.31, 915.29 and 397.70

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Solution

The fourth proportional to 663.31, 915.29 and 397.70 is: 548.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.31 : 915.29 = 397.70 : x
  2. Step 2: Convert to fraction form
    663.31/915.29 = 397.70/x
  3. Step 3: Cross multiply
    663.31x = 915.29 × 397.70
  4. Step 4: Simplify right side
    663.31x = 364,010.83
  5. Step 5: Solve for x
    x = 364,010.83/663.31
  6. Step 6: Final answer
    x = 548.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.