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Finding the Third Proportional to 209 and 278.75

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Solution

The third proportional to 209 and 278.75 is: 371.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    209 : 278.75 = 278.75 : x
  2. Step 2: Convert to fraction form
    209/278.75 = 278.75/x
  3. Step 3: Cross multiply
    209x = 278.75 × 278.75
  4. Step 4: Simplify right side
    209x = 77,701.56
  5. Step 5: Solve for x
    x = 77,701.56/209
  6. Step 6: Final answer
    x = 371.78

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Why These Related Problems?

These problems maintain the same ratio (1.33) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.