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Finding the Fourth Proportional to 643.56, 965.37 and 318.72

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Solution

The fourth proportional to 643.56, 965.37 and 318.72 is: 478.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.56 : 965.37 = 318.72 : x
  2. Step 2: Convert to fraction form
    643.56/965.37 = 318.72/x
  3. Step 3: Cross multiply
    643.56x = 965.37 × 318.72
  4. Step 4: Simplify right side
    643.56x = 307,682.73
  5. Step 5: Solve for x
    x = 307,682.73/643.56
  6. Step 6: Final answer
    x = 478.09

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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.