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Finding the Fourth Proportional to 643.43, 887.11 and 422

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Solution

The fourth proportional to 643.43, 887.11 and 422 is: 581.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.43 : 887.11 = 422 : x
  2. Step 2: Convert to fraction form
    643.43/887.11 = 422/x
  3. Step 3: Cross multiply
    643.43x = 887.11 × 422
  4. Step 4: Simplify right side
    643.43x = 374,360.42
  5. Step 5: Solve for x
    x = 374,360.42/643.43
  6. Step 6: Final answer
    x = 581.82

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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.