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Finding the Fourth Proportional to 638.25, 880.79 and 405.69

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Solution

The fourth proportional to 638.25, 880.79 and 405.69 is: 559.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.25 : 880.79 = 405.69 : x
  2. Step 2: Convert to fraction form
    638.25/880.79 = 405.69/x
  3. Step 3: Cross multiply
    638.25x = 880.79 × 405.69
  4. Step 4: Simplify right side
    638.25x = 357,325.67
  5. Step 5: Solve for x
    x = 357,325.67/638.25
  6. Step 6: Final answer
    x = 559.85

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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.