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Finding the Fourth Proportional to 395.45, 545.72 and 220.80

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Solution

The fourth proportional to 395.45, 545.72 and 220.80 is: 304.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    395.45 : 545.72 = 220.80 : x
  2. Step 2: Convert to fraction form
    395.45/545.72 = 220.80/x
  3. Step 3: Cross multiply
    395.45x = 545.72 × 220.80
  4. Step 4: Simplify right side
    395.45x = 120,494.98
  5. Step 5: Solve for x
    x = 120,494.98/395.45
  6. Step 6: Final answer
    x = 304.70

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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.