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Finding the Fourth Proportional to 111.30, 166.86 and 77.12

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Solution

The fourth proportional to 111.30, 166.86 and 77.12 is: 115.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    111.30 : 166.86 = 77.12 : x
  2. Step 2: Convert to fraction form
    111.30/166.86 = 77.12/x
  3. Step 3: Cross multiply
    111.30x = 166.86 × 77.12
  4. Step 4: Simplify right side
    111.30x = 12,868.24
  5. Step 5: Solve for x
    x = 12,868.24/111.30
  6. Step 6: Final answer
    x = 115.62

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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.