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Finding the Third Proportional to 287 and 311.75

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Solution

The third proportional to 287 and 311.75 is: 338.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    287 : 311.75 = 311.75 : x
  2. Step 2: Convert to fraction form
    287/311.75 = 311.75/x
  3. Step 3: Cross multiply
    287x = 311.75 × 311.75
  4. Step 4: Simplify right side
    287x = 97,188.06
  5. Step 5: Solve for x
    x = 97,188.06/287
  6. Step 6: Final answer
    x = 338.63

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Why These Related Problems?

These problems maintain the same ratio (1.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.