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Finding the Fourth Proportional to 621.15, 857.21 and 372.42

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Solution

The fourth proportional to 621.15, 857.21 and 372.42 is: 513.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.15 : 857.21 = 372.42 : x
  2. Step 2: Convert to fraction form
    621.15/857.21 = 372.42/x
  3. Step 3: Cross multiply
    621.15x = 857.21 × 372.42
  4. Step 4: Simplify right side
    621.15x = 319,246.29
  5. Step 5: Solve for x
    x = 319,246.29/621.15
  6. Step 6: Final answer
    x = 513.96

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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.