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Finding the Fourth Proportional to 621.44, 857.28 and 388.48

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Solution

The fourth proportional to 621.44, 857.28 and 388.48 is: 535.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.44 : 857.28 = 388.48 : x
  2. Step 2: Convert to fraction form
    621.44/857.28 = 388.48/x
  3. Step 3: Cross multiply
    621.44x = 857.28 × 388.48
  4. Step 4: Simplify right side
    621.44x = 333,036.13
  5. Step 5: Solve for x
    x = 333,036.13/621.44
  6. Step 6: Final answer
    x = 535.91

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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.