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Finding the Third Proportional to 378.91 and 511.66

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Solution

The third proportional to 378.91 and 511.66 is: 690.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    378.91 : 511.66 = 511.66 : x
  2. Step 2: Convert to fraction form
    378.91/511.66 = 511.66/x
  3. Step 3: Cross multiply
    378.91x = 511.66 × 511.66
  4. Step 4: Simplify right side
    378.91x = 261,800.11
  5. Step 5: Solve for x
    x = 261,800.11/378.91
  6. Step 6: Final answer
    x = 690.92

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Why These Related Problems?

These problems maintain the same ratio (1.35) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.