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Finding the Fourth Proportional to 643.23, 887.31 and 381.15

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Solution

The fourth proportional to 643.23, 887.31 and 381.15 is: 525.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.23 : 887.31 = 381.15 : x
  2. Step 2: Convert to fraction form
    643.23/887.31 = 381.15/x
  3. Step 3: Cross multiply
    643.23x = 887.31 × 381.15
  4. Step 4: Simplify right side
    643.23x = 338,198.21
  5. Step 5: Solve for x
    x = 338,198.21/643.23
  6. Step 6: Final answer
    x = 525.78

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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.