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Finding the Fourth Proportional to 618.78, 853.62 and 397.62

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Solution

The fourth proportional to 618.78, 853.62 and 397.62 is: 548.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.78 : 853.62 = 397.62 : x
  2. Step 2: Convert to fraction form
    618.78/853.62 = 397.62/x
  3. Step 3: Cross multiply
    618.78x = 853.62 × 397.62
  4. Step 4: Simplify right side
    618.78x = 339,416.38
  5. Step 5: Solve for x
    x = 339,416.38/618.78
  6. Step 6: Final answer
    x = 548.53

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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.