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Finding the Fourth Proportional to 111.66, 154.05 and 72.90

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Solution

The fourth proportional to 111.66, 154.05 and 72.90 is: 100.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    111.66 : 154.05 = 72.90 : x
  2. Step 2: Convert to fraction form
    111.66/154.05 = 72.90/x
  3. Step 3: Cross multiply
    111.66x = 154.05 × 72.90
  4. Step 4: Simplify right side
    111.66x = 11,230.25
  5. Step 5: Solve for x
    x = 11,230.25/111.66
  6. Step 6: Final answer
    x = 100.58

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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.