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Finding the Fourth Proportional to 618.80, 853.84 and 397.64

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Solution

The fourth proportional to 618.80, 853.84 and 397.64 is: 548.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.80 : 853.84 = 397.64 : x
  2. Step 2: Convert to fraction form
    618.80/853.84 = 397.64/x
  3. Step 3: Cross multiply
    618.80x = 853.84 × 397.64
  4. Step 4: Simplify right side
    618.80x = 339,520.94
  5. Step 5: Solve for x
    x = 339,520.94/618.80
  6. Step 6: Final answer
    x = 548.68

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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.