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Finding the Fourth Proportional to 643.21, 965.11 and 313.97

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Solution

The fourth proportional to 643.21, 965.11 and 313.97 is: 471.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.21 : 965.11 = 313.97 : x
  2. Step 2: Convert to fraction form
    643.21/965.11 = 313.97/x
  3. Step 3: Cross multiply
    643.21x = 965.11 × 313.97
  4. Step 4: Simplify right side
    643.21x = 303,009.98
  5. Step 5: Solve for x
    x = 303,009.98/643.21
  6. Step 6: Final answer
    x = 471.09

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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.