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Finding the Fourth Proportional to 621.28, 857.04 and 388.32

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Solution

The fourth proportional to 621.28, 857.04 and 388.32 is: 535.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.28 : 857.04 = 388.32 : x
  2. Step 2: Convert to fraction form
    621.28/857.04 = 388.32/x
  3. Step 3: Cross multiply
    621.28x = 857.04 × 388.32
  4. Step 4: Simplify right side
    621.28x = 332,805.77
  5. Step 5: Solve for x
    x = 332,805.77/621.28
  6. Step 6: Final answer
    x = 535.68

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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.