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Finding the Fourth Proportional to 643.12, 965.64 and 398.96

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Solution

The fourth proportional to 643.12, 965.64 and 398.96 is: 599.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.12 : 965.64 = 398.96 : x
  2. Step 2: Convert to fraction form
    643.12/965.64 = 398.96/x
  3. Step 3: Cross multiply
    643.12x = 965.64 × 398.96
  4. Step 4: Simplify right side
    643.12x = 385,251.73
  5. Step 5: Solve for x
    x = 385,251.73/643.12
  6. Step 6: Final answer
    x = 599.04

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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.