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Finding the Fourth Proportional to 643.91, 965.84 and 447.84

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Solution

The fourth proportional to 643.91, 965.84 and 447.84 is: 671.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.91 : 965.84 = 447.84 : x
  2. Step 2: Convert to fraction form
    643.91/965.84 = 447.84/x
  3. Step 3: Cross multiply
    643.91x = 965.84 × 447.84
  4. Step 4: Simplify right side
    643.91x = 432,539.55
  5. Step 5: Solve for x
    x = 432,539.55/643.91
  6. Step 6: Final answer
    x = 671.74

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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.