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Finding the Fourth Proportional to 396.20, 594.30 and 390.80

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Solution

The fourth proportional to 396.20, 594.30 and 390.80 is: 586.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    396.20 : 594.30 = 390.80 : x
  2. Step 2: Convert to fraction form
    396.20/594.30 = 390.80/x
  3. Step 3: Cross multiply
    396.20x = 594.30 × 390.80
  4. Step 4: Simplify right side
    396.20x = 232,252.44
  5. Step 5: Solve for x
    x = 232,252.44/396.20
  6. Step 6: Final answer
    x = 586.20

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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.