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Finding the Fourth Proportional to 280.19, 420.12 and 131.90

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Solution

The fourth proportional to 280.19, 420.12 and 131.90 is: 197.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.19 : 420.12 = 131.90 : x
  2. Step 2: Convert to fraction form
    280.19/420.12 = 131.90/x
  3. Step 3: Cross multiply
    280.19x = 420.12 × 131.90
  4. Step 4: Simplify right side
    280.19x = 55,411.73
  5. Step 5: Solve for x
    x = 55,411.73/280.19
  6. Step 6: Final answer
    x = 197.76

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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.