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Finding the Fourth Proportional to 149.81, 206.69 and 87.60

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Solution

The fourth proportional to 149.81, 206.69 and 87.60 is: 120.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.81 : 206.69 = 87.60 : x
  2. Step 2: Convert to fraction form
    149.81/206.69 = 87.60/x
  3. Step 3: Cross multiply
    149.81x = 206.69 × 87.60
  4. Step 4: Simplify right side
    149.81x = 18,105.61
  5. Step 5: Solve for x
    x = 18,105.61/149.81
  6. Step 6: Final answer
    x = 120.86

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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.