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Finding the Fourth Proportional to 665.40, 998.28 and 280.56

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Solution

The fourth proportional to 665.40, 998.28 and 280.56 is: 420.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.40 : 998.28 = 280.56 : x
  2. Step 2: Convert to fraction form
    665.40/998.28 = 280.56/x
  3. Step 3: Cross multiply
    665.40x = 998.28 × 280.56
  4. Step 4: Simplify right side
    665.40x = 280,077.44
  5. Step 5: Solve for x
    x = 280,077.44/665.40
  6. Step 6: Final answer
    x = 420.92

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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.