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Finding the Fourth Proportional to 638.73, 954.21 and 405.75

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Solution

The fourth proportional to 638.73, 954.21 and 405.75 is: 606.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.73 : 954.21 = 405.75 : x
  2. Step 2: Convert to fraction form
    638.73/954.21 = 405.75/x
  3. Step 3: Cross multiply
    638.73x = 954.21 × 405.75
  4. Step 4: Simplify right side
    638.73x = 387,170.71
  5. Step 5: Solve for x
    x = 387,170.71/638.73
  6. Step 6: Final answer
    x = 606.16

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.