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Finding the Fourth Proportional to 280.28, 420.32 and 85.27

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Solution

The fourth proportional to 280.28, 420.32 and 85.27 is: 127.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.28 : 420.32 = 85.27 : x
  2. Step 2: Convert to fraction form
    280.28/420.32 = 85.27/x
  3. Step 3: Cross multiply
    280.28x = 420.32 × 85.27
  4. Step 4: Simplify right side
    280.28x = 35,840.69
  5. Step 5: Solve for x
    x = 35,840.69/280.28
  6. Step 6: Final answer
    x = 127.87

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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.