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Finding the Fourth Proportional to 642.31, 963.62 and 209.47

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Solution

The fourth proportional to 642.31, 963.62 and 209.47 is: 314.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.31 : 963.62 = 209.47 : x
  2. Step 2: Convert to fraction form
    642.31/963.62 = 209.47/x
  3. Step 3: Cross multiply
    642.31x = 963.62 × 209.47
  4. Step 4: Simplify right side
    642.31x = 201,849.48
  5. Step 5: Solve for x
    x = 201,849.48/642.31
  6. Step 6: Final answer
    x = 314.26

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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.