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Finding the Fourth Proportional to 665.28, 998 and 280.64

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Solution

The fourth proportional to 665.28, 998 and 280.64 is: 420.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.28 : 998 = 280.64 : x
  2. Step 2: Convert to fraction form
    665.28/998 = 280.64/x
  3. Step 3: Cross multiply
    665.28x = 998 × 280.64
  4. Step 4: Simplify right side
    665.28x = 280,078.72
  5. Step 5: Solve for x
    x = 280,078.72/665.28
  6. Step 6: Final answer
    x = 420.99

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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.