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Finding the Fourth Proportional to 638.46, 958.32 and 442.78

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Solution

The fourth proportional to 638.46, 958.32 and 442.78 is: 664.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.46 : 958.32 = 442.78 : x
  2. Step 2: Convert to fraction form
    638.46/958.32 = 442.78/x
  3. Step 3: Cross multiply
    638.46x = 958.32 × 442.78
  4. Step 4: Simplify right side
    638.46x = 424,322.53
  5. Step 5: Solve for x
    x = 424,322.53/638.46
  6. Step 6: Final answer
    x = 664.60

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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.