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Finding the Fourth Proportional to 618.65, 854.31 and 397.99

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Solution

The fourth proportional to 618.65, 854.31 and 397.99 is: 549.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    618.65 : 854.31 = 397.99 : x
  2. Step 2: Convert to fraction form
    618.65/854.31 = 397.99/x
  3. Step 3: Cross multiply
    618.65x = 854.31 × 397.99
  4. Step 4: Simplify right side
    618.65x = 340,003.56
  5. Step 5: Solve for x
    x = 340,003.56/618.65
  6. Step 6: Final answer
    x = 549.59

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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.