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Finding the Fourth Proportional to 621.42, 857.22 and 385.29

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Solution

The fourth proportional to 621.42, 857.22 and 385.29 is: 531.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.42 : 857.22 = 385.29 : x
  2. Step 2: Convert to fraction form
    621.42/857.22 = 385.29/x
  3. Step 3: Cross multiply
    621.42x = 857.22 × 385.29
  4. Step 4: Simplify right side
    621.42x = 330,280.10
  5. Step 5: Solve for x
    x = 330,280.10/621.42
  6. Step 6: Final answer
    x = 531.49

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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.