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Finding the Fourth Proportional to 398.31, 549.48 and 287.61

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Solution

The fourth proportional to 398.31, 549.48 and 287.61 is: 396.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.31 : 549.48 = 287.61 : x
  2. Step 2: Convert to fraction form
    398.31/549.48 = 287.61/x
  3. Step 3: Cross multiply
    398.31x = 549.48 × 287.61
  4. Step 4: Simplify right side
    398.31x = 158,035.94
  5. Step 5: Solve for x
    x = 158,035.94/398.31
  6. Step 6: Final answer
    x = 396.77

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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.