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Finding the Third Proportional to 640.50 and 842.25

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Solution

The third proportional to 640.50 and 842.25 is: 1,107.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.50 : 842.25 = 842.25 : x
  2. Step 2: Convert to fraction form
    640.50/842.25 = 842.25/x
  3. Step 3: Cross multiply
    640.50x = 842.25 × 842.25
  4. Step 4: Simplify right side
    640.50x = 709,385.06
  5. Step 5: Solve for x
    x = 709,385.06/640.50
  6. Step 6: Final answer
    x = 1,107.55

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Why These Related Problems?

These problems maintain the same ratio (1.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.