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Finding the Fourth Proportional to 485.87, 728.80 and 403.85

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Solution

The fourth proportional to 485.87, 728.80 and 403.85 is: 605.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.87 : 728.80 = 403.85 : x
  2. Step 2: Convert to fraction form
    485.87/728.80 = 403.85/x
  3. Step 3: Cross multiply
    485.87x = 728.80 × 403.85
  4. Step 4: Simplify right side
    485.87x = 294,326.69
  5. Step 5: Solve for x
    x = 294,326.69/485.87
  6. Step 6: Final answer
    x = 605.78

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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.