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Finding the Third Proportional to 405.91 and 645.29

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Solution

The third proportional to 405.91 and 645.29 is: 1,025.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.91 : 645.29 = 645.29 : x
  2. Step 2: Convert to fraction form
    405.91/645.29 = 645.29/x
  3. Step 3: Cross multiply
    405.91x = 645.29 × 645.29
  4. Step 4: Simplify right side
    405.91x = 416,400.18
  5. Step 5: Solve for x
    x = 416,400.18/405.91
  6. Step 6: Final answer
    x = 1,025.84

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Why These Related Problems?

These problems maintain the same ratio (1.59) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.