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Finding the Fourth Proportional to 642.43, 963.66 and 209.57

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Solution

The fourth proportional to 642.43, 963.66 and 209.57 is: 314.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.43 : 963.66 = 209.57 : x
  2. Step 2: Convert to fraction form
    642.43/963.66 = 209.57/x
  3. Step 3: Cross multiply
    642.43x = 963.66 × 209.57
  4. Step 4: Simplify right side
    642.43x = 201,954.23
  5. Step 5: Solve for x
    x = 201,954.23/642.43
  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.