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Finding the Fourth Proportional to 643.56, 887.60 and 422.43

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Solution

The fourth proportional to 643.56, 887.60 and 422.43 is: 582.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.56 : 887.60 = 422.43 : x
  2. Step 2: Convert to fraction form
    643.56/887.60 = 422.43/x
  3. Step 3: Cross multiply
    643.56x = 887.60 × 422.43
  4. Step 4: Simplify right side
    643.56x = 374,946.76
  5. Step 5: Solve for x
    x = 374,946.76/643.56
  6. Step 6: Final answer
    x = 582.61

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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.