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Finding the Fourth Proportional to 643.26, 886.76 and 394.42

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Solution

The fourth proportional to 643.26, 886.76 and 394.42 is: 543.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.26 : 886.76 = 394.42 : x
  2. Step 2: Convert to fraction form
    643.26/886.76 = 394.42/x
  3. Step 3: Cross multiply
    643.26x = 886.76 × 394.42
  4. Step 4: Simplify right side
    643.26x = 349,755.88
  5. Step 5: Solve for x
    x = 349,755.88/643.26
  6. Step 6: Final answer
    x = 543.72

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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.