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Finding the Fourth Proportional to 639.36, 957.96 and 422.55

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Solution

The fourth proportional to 639.36, 957.96 and 422.55 is: 633.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.36 : 957.96 = 422.55 : x
  2. Step 2: Convert to fraction form
    639.36/957.96 = 422.55/x
  3. Step 3: Cross multiply
    639.36x = 957.96 × 422.55
  4. Step 4: Simplify right side
    639.36x = 404,786.00
  5. Step 5: Solve for x
    x = 404,786.00/639.36
  6. Step 6: Final answer
    x = 633.11

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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.