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Finding the Fourth Proportional to 426.30, 639.12 and 252.72

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Solution

The fourth proportional to 426.30, 639.12 and 252.72 is: 378.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.30 : 639.12 = 252.72 : x
  2. Step 2: Convert to fraction form
    426.30/639.12 = 252.72/x
  3. Step 3: Cross multiply
    426.30x = 639.12 × 252.72
  4. Step 4: Simplify right side
    426.30x = 161,518.41
  5. Step 5: Solve for x
    x = 161,518.41/426.30
  6. Step 6: Final answer
    x = 378.88

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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.