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Finding the Fourth Proportional to 618.12, 853.20 and 397.20

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Solution

The fourth proportional to 618.12, 853.20 and 397.20 is: 548.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.12 : 853.20 = 397.20 : x
  2. Step 2: Convert to fraction form
    618.12/853.20 = 397.20/x
  3. Step 3: Cross multiply
    618.12x = 853.20 × 397.20
  4. Step 4: Simplify right side
    618.12x = 338,891.04
  5. Step 5: Solve for x
    x = 338,891.04/618.12
  6. Step 6: Final answer
    x = 548.26

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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.