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Finding the Fourth Proportional to 643.88, 965.82 and 211.05

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Solution

The fourth proportional to 643.88, 965.82 and 211.05 is: 316.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.88 : 965.82 = 211.05 : x
  2. Step 2: Convert to fraction form
    643.88/965.82 = 211.05/x
  3. Step 3: Cross multiply
    643.88x = 965.82 × 211.05
  4. Step 4: Simplify right side
    643.88x = 203,836.31
  5. Step 5: Solve for x
    x = 203,836.31/643.88
  6. Step 6: Final answer
    x = 316.58

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.