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Finding the Fourth Proportional to 394.91, 545.18 and 312.29

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Solution

The fourth proportional to 394.91, 545.18 and 312.29 is: 431.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    394.91 : 545.18 = 312.29 : x
  2. Step 2: Convert to fraction form
    394.91/545.18 = 312.29/x
  3. Step 3: Cross multiply
    394.91x = 545.18 × 312.29
  4. Step 4: Simplify right side
    394.91x = 170,249.97
  5. Step 5: Solve for x
    x = 170,249.97/394.91
  6. Step 6: Final answer
    x = 431.12

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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.