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Finding the Fourth Proportional to 409.44, 618.78 and 405.12

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Solution

The fourth proportional to 409.44, 618.78 and 405.12 is: 612.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.44 : 618.78 = 405.12 : x
  2. Step 2: Convert to fraction form
    409.44/618.78 = 405.12/x
  3. Step 3: Cross multiply
    409.44x = 618.78 × 405.12
  4. Step 4: Simplify right side
    409.44x = 250,680.15
  5. Step 5: Solve for x
    x = 250,680.15/409.44
  6. Step 6: Final answer
    x = 612.25

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.