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Finding the Third Proportional to 643.15 and 1,388.81

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Solution

The third proportional to 643.15 and 1,388.81 is: 2,999.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.15 : 1,388.81 = 1,388.81 : x
  2. Step 2: Convert to fraction form
    643.15/1,388.81 = 1,388.81/x
  3. Step 3: Cross multiply
    643.15x = 1,388.81 × 1,388.81
  4. Step 4: Simplify right side
    643.15x = 1,928,800.16
  5. Step 5: Solve for x
    x = 1,928,800.16/643.15
  6. Step 6: Final answer
    x = 2,999.00

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Why These Related Problems?

These problems maintain the same ratio (2.16) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.