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Finding the Fourth Proportional to 639.44, 957.72 and 447.92

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Solution

The fourth proportional to 639.44, 957.72 and 447.92 is: 670.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.44 : 957.72 = 447.92 : x
  2. Step 2: Convert to fraction form
    639.44/957.72 = 447.92/x
  3. Step 3: Cross multiply
    639.44x = 957.72 × 447.92
  4. Step 4: Simplify right side
    639.44x = 428,981.94
  5. Step 5: Solve for x
    x = 428,981.94/639.44
  6. Step 6: Final answer
    x = 670.87

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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.