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Finding the Fourth Proportional to 642.57, 963.96 and 209.63

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Solution

The fourth proportional to 642.57, 963.96 and 209.63 is: 314.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.57 : 963.96 = 209.63 : x
  2. Step 2: Convert to fraction form
    642.57/963.96 = 209.63/x
  3. Step 3: Cross multiply
    642.57x = 963.96 × 209.63
  4. Step 4: Simplify right side
    642.57x = 202,070.12
  5. Step 5: Solve for x
    x = 202,070.12/642.57
  6. Step 6: Final answer
    x = 314.47

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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.