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Finding the Fourth Proportional to 485.89, 728.15 and 280.51

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Solution

The fourth proportional to 485.89, 728.15 and 280.51 is: 420.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.89 : 728.15 = 280.51 : x
  2. Step 2: Convert to fraction form
    485.89/728.15 = 280.51/x
  3. Step 3: Cross multiply
    485.89x = 728.15 × 280.51
  4. Step 4: Simplify right side
    485.89x = 204,250.13
  5. Step 5: Solve for x
    x = 204,250.13/485.89
  6. Step 6: Final answer
    x = 420.37

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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.