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Finding the Fourth Proportional to 618.84, 853.83 and 398.09

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Solution

The fourth proportional to 618.84, 853.83 and 398.09 is: 549.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.84 : 853.83 = 398.09 : x
  2. Step 2: Convert to fraction form
    618.84/853.83 = 398.09/x
  3. Step 3: Cross multiply
    618.84x = 853.83 × 398.09
  4. Step 4: Simplify right side
    618.84x = 339,903.32
  5. Step 5: Solve for x
    x = 339,903.32/618.84
  6. Step 6: Final answer
    x = 549.26

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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.