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Finding the Fourth Proportional to 409.78, 613.75 and 318.20

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Solution

The fourth proportional to 409.78, 613.75 and 318.20 is: 476.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.78 : 613.75 = 318.20 : x
  2. Step 2: Convert to fraction form
    409.78/613.75 = 318.20/x
  3. Step 3: Cross multiply
    409.78x = 613.75 × 318.20
  4. Step 4: Simplify right side
    409.78x = 195,292.92
  5. Step 5: Solve for x
    x = 195,292.92/409.78
  6. Step 6: Final answer
    x = 476.58

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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.