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Finding the Fourth Proportional to 643.28, 887.15 and 418.97

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Solution

The fourth proportional to 643.28, 887.15 and 418.97 is: 577.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.28 : 887.15 = 418.97 : x
  2. Step 2: Convert to fraction form
    643.28/887.15 = 418.97/x
  3. Step 3: Cross multiply
    643.28x = 887.15 × 418.97
  4. Step 4: Simplify right side
    643.28x = 371,692.50
  5. Step 5: Solve for x
    x = 371,692.50/643.28
  6. Step 6: Final answer
    x = 577.81

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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.