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Finding the Fourth Proportional to 643.92, 964.42 and 318.56

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Solution

The fourth proportional to 643.92, 964.42 and 318.56 is: 477.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.92 : 964.42 = 318.56 : x
  2. Step 2: Convert to fraction form
    643.92/964.42 = 318.56/x
  3. Step 3: Cross multiply
    643.92x = 964.42 × 318.56
  4. Step 4: Simplify right side
    643.92x = 307,225.64
  5. Step 5: Solve for x
    x = 307,225.64/643.92
  6. Step 6: Final answer
    x = 477.12

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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.