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Finding the Fourth Proportional to 298.62, 408.30 and 287.28

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Solution

The fourth proportional to 298.62, 408.30 and 287.28 is: 392.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    298.62 : 408.30 = 287.28 : x
  2. Step 2: Convert to fraction form
    298.62/408.30 = 287.28/x
  3. Step 3: Cross multiply
    298.62x = 408.30 × 287.28
  4. Step 4: Simplify right side
    298.62x = 117,296.42
  5. Step 5: Solve for x
    x = 117,296.42/298.62
  6. Step 6: Final answer
    x = 392.79

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.