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Finding the Fourth Proportional to 642.61, 963.82 and 209.71

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Solution

The fourth proportional to 642.61, 963.82 and 209.71 is: 314.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.61 : 963.82 = 209.71 : x
  2. Step 2: Convert to fraction form
    642.61/963.82 = 209.71/x
  3. Step 3: Cross multiply
    642.61x = 963.82 × 209.71
  4. Step 4: Simplify right side
    642.61x = 202,122.69
  5. Step 5: Solve for x
    x = 202,122.69/642.61
  6. Step 6: Final answer
    x = 314.53

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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.