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Finding the Fourth Proportional to 642.72, 963.84 and 318.24

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Solution

The fourth proportional to 642.72, 963.84 and 318.24 is: 477.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.72 : 963.84 = 318.24 : x
  2. Step 2: Convert to fraction form
    642.72/963.84 = 318.24/x
  3. Step 3: Cross multiply
    642.72x = 963.84 × 318.24
  4. Step 4: Simplify right side
    642.72x = 306,732.44
  5. Step 5: Solve for x
    x = 306,732.44/642.72
  6. Step 6: Final answer
    x = 477.24

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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.