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Finding the Fourth Proportional to 408.72, 613.64 and 278.36

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Solution

The fourth proportional to 408.72, 613.64 and 278.36 is: 417.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.72 : 613.64 = 278.36 : x
  2. Step 2: Convert to fraction form
    408.72/613.64 = 278.36/x
  3. Step 3: Cross multiply
    408.72x = 613.64 × 278.36
  4. Step 4: Simplify right side
    408.72x = 170,812.83
  5. Step 5: Solve for x
    x = 170,812.83/408.72
  6. Step 6: Final answer
    x = 417.92

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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.