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Finding the Fourth Proportional to 149.49, 206.10 and 121.80

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Solution

The fourth proportional to 149.49, 206.10 and 121.80 is: 167.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.49 : 206.10 = 121.80 : x
  2. Step 2: Convert to fraction form
    149.49/206.10 = 121.80/x
  3. Step 3: Cross multiply
    149.49x = 206.10 × 121.80
  4. Step 4: Simplify right side
    149.49x = 25,102.98
  5. Step 5: Solve for x
    x = 25,102.98/149.49
  6. Step 6: Final answer
    x = 167.92

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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.