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Finding the Fourth Proportional to 77.22, 115.20 and 71.15

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Solution

The fourth proportional to 77.22, 115.20 and 71.15 is: 106.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.22 : 115.20 = 71.15 : x
  2. Step 2: Convert to fraction form
    77.22/115.20 = 71.15/x
  3. Step 3: Cross multiply
    77.22x = 115.20 × 71.15
  4. Step 4: Simplify right side
    77.22x = 8,195.90
  5. Step 5: Solve for x
    x = 8,195.90/77.22
  6. Step 6: Final answer
    x = 106.14

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.