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Finding the Fourth Proportional to 639.49, 957.72 and 395.28

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Solution

The fourth proportional to 639.49, 957.72 and 395.28 is: 591.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.49 : 957.72 = 395.28 : x
  2. Step 2: Convert to fraction form
    639.49/957.72 = 395.28/x
  3. Step 3: Cross multiply
    639.49x = 957.72 × 395.28
  4. Step 4: Simplify right side
    639.49x = 378,567.56
  5. Step 5: Solve for x
    x = 378,567.56/639.49
  6. Step 6: Final answer
    x = 591.98

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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.