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Finding the Fourth Proportional to 642.49, 963.88 and 209.54

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Solution

The fourth proportional to 642.49, 963.88 and 209.54 is: 314.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.49 : 963.88 = 209.54 : x
  2. Step 2: Convert to fraction form
    642.49/963.88 = 209.54/x
  3. Step 3: Cross multiply
    642.49x = 963.88 × 209.54
  4. Step 4: Simplify right side
    642.49x = 201,973.30
  5. Step 5: Solve for x
    x = 201,973.30/642.49
  6. Step 6: Final answer
    x = 314.36

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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.