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Finding the Fourth Proportional to 639.46, 957.30 and 395.20

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Solution

The fourth proportional to 639.46, 957.30 and 395.20 is: 591.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.46 : 957.30 = 395.20 : x
  2. Step 2: Convert to fraction form
    639.46/957.30 = 395.20/x
  3. Step 3: Cross multiply
    639.46x = 957.30 × 395.20
  4. Step 4: Simplify right side
    639.46x = 378,324.96
  5. Step 5: Solve for x
    x = 378,324.96/639.46
  6. Step 6: Final answer
    x = 591.63

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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.