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Finding the Third Proportional to 208.78 and 430.78

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Solution

The third proportional to 208.78 and 430.78 is: 888.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.78 : 430.78 = 430.78 : x
  2. Step 2: Convert to fraction form
    208.78/430.78 = 430.78/x
  3. Step 3: Cross multiply
    208.78x = 430.78 × 430.78
  4. Step 4: Simplify right side
    208.78x = 185,572.49
  5. Step 5: Solve for x
    x = 185,572.49/208.78
  6. Step 6: Final answer
    x = 888.84

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Why These Related Problems?

These problems maintain the same ratio (2.06) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.