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Finding the Fourth Proportional to 642.30, 963.66 and 209.76

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Solution

The fourth proportional to 642.30, 963.66 and 209.76 is: 314.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.30 : 963.66 = 209.76 : x
  2. Step 2: Convert to fraction form
    642.30/963.66 = 209.76/x
  3. Step 3: Cross multiply
    642.30x = 963.66 × 209.76
  4. Step 4: Simplify right side
    642.30x = 202,137.32
  5. Step 5: Solve for x
    x = 202,137.32/642.30
  6. Step 6: Final answer
    x = 314.71

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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.