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Finding the Fourth Proportional to 621.68, 857.66 and 385.54

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Solution

The fourth proportional to 621.68, 857.66 and 385.54 is: 531.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.68 : 857.66 = 385.54 : x
  2. Step 2: Convert to fraction form
    621.68/857.66 = 385.54/x
  3. Step 3: Cross multiply
    621.68x = 857.66 × 385.54
  4. Step 4: Simplify right side
    621.68x = 330,662.24
  5. Step 5: Solve for x
    x = 330,662.24/621.68
  6. Step 6: Final answer
    x = 531.88

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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.