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Finding the Third Proportional to 621.09 and 870.47

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Solution

The third proportional to 621.09 and 870.47 is: 1,219.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.09 : 870.47 = 870.47 : x
  2. Step 2: Convert to fraction form
    621.09/870.47 = 870.47/x
  3. Step 3: Cross multiply
    621.09x = 870.47 × 870.47
  4. Step 4: Simplify right side
    621.09x = 757,715.84
  5. Step 5: Solve for x
    x = 757,715.84/621.09
  6. Step 6: Final answer
    x = 1,219.97

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Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.