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Finding the Fourth Proportional to 280.45, 387.03 and 156.11

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Solution

The fourth proportional to 280.45, 387.03 and 156.11 is: 215.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.45 : 387.03 = 156.11 : x
  2. Step 2: Convert to fraction form
    280.45/387.03 = 156.11/x
  3. Step 3: Cross multiply
    280.45x = 387.03 × 156.11
  4. Step 4: Simplify right side
    280.45x = 60,416.73
  5. Step 5: Solve for x
    x = 60,416.73/280.45
  6. Step 6: Final answer
    x = 215.43

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.