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Finding the Fourth Proportional to 642.20, 963.48 and 209.34

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Solution

The fourth proportional to 642.20, 963.48 and 209.34 is: 314.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.20 : 963.48 = 209.34 : x
  2. Step 2: Convert to fraction form
    642.20/963.48 = 209.34/x
  3. Step 3: Cross multiply
    642.20x = 963.48 × 209.34
  4. Step 4: Simplify right side
    642.20x = 201,694.90
  5. Step 5: Solve for x
    x = 201,694.90/642.20
  6. Step 6: Final answer
    x = 314.07

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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.