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Finding the Fourth Proportional to 643.26, 964.89 and 318.72

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Solution

The fourth proportional to 643.26, 964.89 and 318.72 is: 478.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.26 : 964.89 = 318.72 : x
  2. Step 2: Convert to fraction form
    643.26/964.89 = 318.72/x
  3. Step 3: Cross multiply
    643.26x = 964.89 × 318.72
  4. Step 4: Simplify right side
    643.26x = 307,529.74
  5. Step 5: Solve for x
    x = 307,529.74/643.26
  6. Step 6: Final answer
    x = 478.08

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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.