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Finding the Fourth Proportional to 409.19, 612.90 and 255.15

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Solution

The fourth proportional to 409.19, 612.90 and 255.15 is: 382.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.19 : 612.90 = 255.15 : x
  2. Step 2: Convert to fraction form
    409.19/612.90 = 255.15/x
  3. Step 3: Cross multiply
    409.19x = 612.90 × 255.15
  4. Step 4: Simplify right side
    409.19x = 156,381.44
  5. Step 5: Solve for x
    x = 156,381.44/409.19
  6. Step 6: Final answer
    x = 382.18

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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.