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Finding the Fourth Proportional to 442.20, 662.70 and 257.20

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Solution

The fourth proportional to 442.20, 662.70 and 257.20 is: 385.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    442.20 : 662.70 = 257.20 : x
  2. Step 2: Convert to fraction form
    442.20/662.70 = 257.20/x
  3. Step 3: Cross multiply
    442.20x = 662.70 × 257.20
  4. Step 4: Simplify right side
    442.20x = 170,446.44
  5. Step 5: Solve for x
    x = 170,446.44/442.20
  6. Step 6: Final answer
    x = 385.45

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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.