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Finding the Fourth Proportional to 642.62, 963.99 and 209.75

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Solution

The fourth proportional to 642.62, 963.99 and 209.75 is: 314.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.62 : 963.99 = 209.75 : x
  2. Step 2: Convert to fraction form
    642.62/963.99 = 209.75/x
  3. Step 3: Cross multiply
    642.62x = 963.99 × 209.75
  4. Step 4: Simplify right side
    642.62x = 202,196.90
  5. Step 5: Solve for x
    x = 202,196.90/642.62
  6. Step 6: Final answer
    x = 314.64

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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.