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Finding the Fourth Proportional to 638.67, 881.04 and 428.90

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Solution

The fourth proportional to 638.67, 881.04 and 428.90 is: 591.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.67 : 881.04 = 428.90 : x
  2. Step 2: Convert to fraction form
    638.67/881.04 = 428.90/x
  3. Step 3: Cross multiply
    638.67x = 881.04 × 428.90
  4. Step 4: Simplify right side
    638.67x = 377,875.26
  5. Step 5: Solve for x
    x = 377,875.26/638.67
  6. Step 6: Final answer
    x = 591.66

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.