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Finding the Fourth Proportional to 485.72, 728.76 and 225.85

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Solution

The fourth proportional to 485.72, 728.76 and 225.85 is: 338.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.72 : 728.76 = 225.85 : x
  2. Step 2: Convert to fraction form
    485.72/728.76 = 225.85/x
  3. Step 3: Cross multiply
    485.72x = 728.76 × 225.85
  4. Step 4: Simplify right side
    485.72x = 164,590.45
  5. Step 5: Solve for x
    x = 164,590.45/485.72
  6. Step 6: Final answer
    x = 338.86

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.