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Finding the Fourth Proportional to 642.91, 964.45 and 209.96

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Solution

The fourth proportional to 642.91, 964.45 and 209.96 is: 314.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.91 : 964.45 = 209.96 : x
  2. Step 2: Convert to fraction form
    642.91/964.45 = 209.96/x
  3. Step 3: Cross multiply
    642.91x = 964.45 × 209.96
  4. Step 4: Simplify right side
    642.91x = 202,495.92
  5. Step 5: Solve for x
    x = 202,495.92/642.91
  6. Step 6: Final answer
    x = 314.97

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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.