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Finding the Fourth Proportional to 621.87, 858.23 and 401.28

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Solution

The fourth proportional to 621.87, 858.23 and 401.28 is: 553.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.87 : 858.23 = 401.28 : x
  2. Step 2: Convert to fraction form
    621.87/858.23 = 401.28/x
  3. Step 3: Cross multiply
    621.87x = 858.23 × 401.28
  4. Step 4: Simplify right side
    621.87x = 344,390.53
  5. Step 5: Solve for x
    x = 344,390.53/621.87
  6. Step 6: Final answer
    x = 553.80

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.