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Finding the Fourth Proportional to 618.45, 853.32 and 397.65

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Solution

The fourth proportional to 618.45, 853.32 and 397.65 is: 548.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.45 : 853.32 = 397.65 : x
  2. Step 2: Convert to fraction form
    618.45/853.32 = 397.65/x
  3. Step 3: Cross multiply
    618.45x = 853.32 × 397.65
  4. Step 4: Simplify right side
    618.45x = 339,322.70
  5. Step 5: Solve for x
    x = 339,322.70/618.45
  6. Step 6: Final answer
    x = 548.67

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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.