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Finding the Fourth Proportional to 643.28, 965.23 and 318.88

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Solution

The fourth proportional to 643.28, 965.23 and 318.88 is: 478.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.28 : 965.23 = 318.88 : x
  2. Step 2: Convert to fraction form
    643.28/965.23 = 318.88/x
  3. Step 3: Cross multiply
    643.28x = 965.23 × 318.88
  4. Step 4: Simplify right side
    643.28x = 307,789.33
  5. Step 5: Solve for x
    x = 307,789.33/643.28
  6. Step 6: Final answer
    x = 478.47

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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.