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Finding the Fourth Proportional to 411.73, 618.13 and 257.20

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Solution

The fourth proportional to 411.73, 618.13 and 257.20 is: 386.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    411.73 : 618.13 = 257.20 : x
  2. Step 2: Convert to fraction form
    411.73/618.13 = 257.20/x
  3. Step 3: Cross multiply
    411.73x = 618.13 × 257.20
  4. Step 4: Simplify right side
    411.73x = 158,983.55
  5. Step 5: Solve for x
    x = 158,983.55/411.73
  6. Step 6: Final answer
    x = 386.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.