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Finding the Fourth Proportional to 621.64, 857.28 and 490.96

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Solution

The fourth proportional to 621.64, 857.28 and 490.96 is: 677.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.64 : 857.28 = 490.96 : x
  2. Step 2: Convert to fraction form
    621.64/857.28 = 490.96/x
  3. Step 3: Cross multiply
    621.64x = 857.28 × 490.96
  4. Step 4: Simplify right side
    621.64x = 420,890.19
  5. Step 5: Solve for x
    x = 420,890.19/621.64
  6. Step 6: Final answer
    x = 677.06

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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.