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Finding the Fourth Proportional to 398.98, 551.20 and 306.10

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Solution

The fourth proportional to 398.98, 551.20 and 306.10 is: 422.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.98 : 551.20 = 306.10 : x
  2. Step 2: Convert to fraction form
    398.98/551.20 = 306.10/x
  3. Step 3: Cross multiply
    398.98x = 551.20 × 306.10
  4. Step 4: Simplify right side
    398.98x = 168,722.32
  5. Step 5: Solve for x
    x = 168,722.32/398.98
  6. Step 6: Final answer
    x = 422.88

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.