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Finding the Fourth Proportional to 121.28, 181.90 and 67.16

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Solution

The fourth proportional to 121.28, 181.90 and 67.16 is: 100.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.28 : 181.90 = 67.16 : x
  2. Step 2: Convert to fraction form
    121.28/181.90 = 67.16/x
  3. Step 3: Cross multiply
    121.28x = 181.90 × 67.16
  4. Step 4: Simplify right side
    121.28x = 12,216.40
  5. Step 5: Solve for x
    x = 12,216.40/121.28
  6. Step 6: Final answer
    x = 100.73

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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.