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Finding the Third Proportional to 311 and 490.25

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Solution

The third proportional to 311 and 490.25 is: 772.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    311 : 490.25 = 490.25 : x
  2. Step 2: Convert to fraction form
    311/490.25 = 490.25/x
  3. Step 3: Cross multiply
    311x = 490.25 × 490.25
  4. Step 4: Simplify right side
    311x = 240,345.06
  5. Step 5: Solve for x
    x = 240,345.06/311
  6. Step 6: Final answer
    x = 772.81

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Why These Related Problems?

These problems maintain the same ratio (1.58) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.