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Finding the Fourth Proportional to 642.73, 964.11 and 209.89

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Solution

The fourth proportional to 642.73, 964.11 and 209.89 is: 314.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.73 : 964.11 = 209.89 : x
  2. Step 2: Convert to fraction form
    642.73/964.11 = 209.89/x
  3. Step 3: Cross multiply
    642.73x = 964.11 × 209.89
  4. Step 4: Simplify right side
    642.73x = 202,357.05
  5. Step 5: Solve for x
    x = 202,357.05/642.73
  6. Step 6: Final answer
    x = 314.84

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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.