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Finding the Fourth Proportional to 394.70, 545.15 and 321.30

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Solution

The fourth proportional to 394.70, 545.15 and 321.30 is: 443.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    394.70 : 545.15 = 321.30 : x
  2. Step 2: Convert to fraction form
    394.70/545.15 = 321.30/x
  3. Step 3: Cross multiply
    394.70x = 545.15 × 321.30
  4. Step 4: Simplify right side
    394.70x = 175,157.50
  5. Step 5: Solve for x
    x = 175,157.50/394.70
  6. Step 6: Final answer
    x = 443.78

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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.