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Finding the Fourth Proportional to 618.80, 853.92 and 397.88

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Solution

The fourth proportional to 618.80, 853.92 and 397.88 is: 549.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.80 : 853.92 = 397.88 : x
  2. Step 2: Convert to fraction form
    618.80/853.92 = 397.88/x
  3. Step 3: Cross multiply
    618.80x = 853.92 × 397.88
  4. Step 4: Simplify right side
    618.80x = 339,757.69
  5. Step 5: Solve for x
    x = 339,757.69/618.80
  6. Step 6: Final answer
    x = 549.06

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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.