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Finding the Fourth Proportional to 621.89, 858.20 and 342.12

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Solution

The fourth proportional to 621.89, 858.20 and 342.12 is: 472.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.89 : 858.20 = 342.12 : x
  2. Step 2: Convert to fraction form
    621.89/858.20 = 342.12/x
  3. Step 3: Cross multiply
    621.89x = 858.20 × 342.12
  4. Step 4: Simplify right side
    621.89x = 293,605.67
  5. Step 5: Solve for x
    x = 293,605.67/621.89
  6. Step 6: Final answer
    x = 472.12

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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.