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Finding the Fourth Proportional to 638.67, 881.66 and 428.99

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Solution

The fourth proportional to 638.67, 881.66 and 428.99 is: 592.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.67 : 881.66 = 428.99 : x
  2. Step 2: Convert to fraction form
    638.67/881.66 = 428.99/x
  3. Step 3: Cross multiply
    638.67x = 881.66 × 428.99
  4. Step 4: Simplify right side
    638.67x = 378,221.18
  5. Step 5: Solve for x
    x = 378,221.18/638.67
  6. Step 6: Final answer
    x = 592.20

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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.