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Finding the Fourth Proportional to 638.61, 957.91 and 422.13

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Solution

The fourth proportional to 638.61, 957.91 and 422.13 is: 633.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.61 : 957.91 = 422.13 : x
  2. Step 2: Convert to fraction form
    638.61/957.91 = 422.13/x
  3. Step 3: Cross multiply
    638.61x = 957.91 × 422.13
  4. Step 4: Simplify right side
    638.61x = 404,362.55
  5. Step 5: Solve for x
    x = 404,362.55/638.61
  6. Step 6: Final answer
    x = 633.19

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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.