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Finding the Fourth Proportional to 485.61, 728.41 and 280.05

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Solution

The fourth proportional to 485.61, 728.41 and 280.05 is: 420.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.61 : 728.41 = 280.05 : x
  2. Step 2: Convert to fraction form
    485.61/728.41 = 280.05/x
  3. Step 3: Cross multiply
    485.61x = 728.41 × 280.05
  4. Step 4: Simplify right side
    485.61x = 203,991.22
  5. Step 5: Solve for x
    x = 203,991.22/485.61
  6. Step 6: Final answer
    x = 420.07

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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.