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Finding the Fourth Proportional to 643.80, 888.36 and 381.96

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Solution

The fourth proportional to 643.80, 888.36 and 381.96 is: 527.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.80 : 888.36 = 381.96 : x
  2. Step 2: Convert to fraction form
    643.80/888.36 = 381.96/x
  3. Step 3: Cross multiply
    643.80x = 888.36 × 381.96
  4. Step 4: Simplify right side
    643.80x = 339,317.99
  5. Step 5: Solve for x
    x = 339,317.99/643.80
  6. Step 6: Final answer
    x = 527.05

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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.