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Finding the Fourth Proportional to 186.78, 280.20 and 109.80

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Solution

The fourth proportional to 186.78, 280.20 and 109.80 is: 164.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    186.78 : 280.20 = 109.80 : x
  2. Step 2: Convert to fraction form
    186.78/280.20 = 109.80/x
  3. Step 3: Cross multiply
    186.78x = 280.20 × 109.80
  4. Step 4: Simplify right side
    186.78x = 30,765.96
  5. Step 5: Solve for x
    x = 30,765.96/186.78
  6. Step 6: Final answer
    x = 164.72

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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.