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Finding the Fourth Proportional to 618.88, 853.88 and 398.08

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Solution

The fourth proportional to 618.88, 853.88 and 398.08 is: 549.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.88 : 853.88 = 398.08 : x
  2. Step 2: Convert to fraction form
    618.88/853.88 = 398.08/x
  3. Step 3: Cross multiply
    618.88x = 853.88 × 398.08
  4. Step 4: Simplify right side
    618.88x = 339,912.55
  5. Step 5: Solve for x
    x = 339,912.55/618.88
  6. Step 6: Final answer
    x = 549.24

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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.