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Finding the Fourth Proportional to 664.20, 915.21 and 618.06

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Solution

The fourth proportional to 664.20, 915.21 and 618.06 is: 851.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.20 : 915.21 = 618.06 : x
  2. Step 2: Convert to fraction form
    664.20/915.21 = 618.06/x
  3. Step 3: Cross multiply
    664.20x = 915.21 × 618.06
  4. Step 4: Simplify right side
    664.20x = 565,654.69
  5. Step 5: Solve for x
    x = 565,654.69/664.20
  6. Step 6: Final answer
    x = 851.63

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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.