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Finding the Fourth Proportional to 280.08, 420.20 and 109.20

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Solution

The fourth proportional to 280.08, 420.20 and 109.20 is: 163.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.08 : 420.20 = 109.20 : x
  2. Step 2: Convert to fraction form
    280.08/420.20 = 109.20/x
  3. Step 3: Cross multiply
    280.08x = 420.20 × 109.20
  4. Step 4: Simplify right side
    280.08x = 45,885.84
  5. Step 5: Solve for x
    x = 45,885.84/280.08
  6. Step 6: Final answer
    x = 163.83

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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.