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Finding the Fourth Proportional to 621.70, 872 and 621.70

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Solution

The fourth proportional to 621.70, 872 and 621.70 is: 872

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.70 : 872 = 621.70 : x
  2. Step 2: Convert to fraction form
    621.70/872 = 621.70/x
  3. Step 3: Cross multiply
    621.70x = 872 × 621.70
  4. Step 4: Simplify right side
    621.70x = 542,122.40
  5. Step 5: Solve for x
    x = 542,122.40/621.70
  6. Step 6: Final answer
    x = 872

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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.