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Finding the Fourth Proportional to 621.52, 857.72 and 400.90

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Solution

The fourth proportional to 621.52, 857.72 and 400.90 is: 553.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.52 : 857.72 = 400.90 : x
  2. Step 2: Convert to fraction form
    621.52/857.72 = 400.90/x
  3. Step 3: Cross multiply
    621.52x = 857.72 × 400.90
  4. Step 4: Simplify right side
    621.52x = 343,859.95
  5. Step 5: Solve for x
    x = 343,859.95/621.52
  6. Step 6: Final answer
    x = 553.26

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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.