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Finding the Fourth Proportional to 77.10, 106.29 and 71.70

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Solution

The fourth proportional to 77.10, 106.29 and 71.70 is: 98.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.10 : 106.29 = 71.70 : x
  2. Step 2: Convert to fraction form
    77.10/106.29 = 71.70/x
  3. Step 3: Cross multiply
    77.10x = 106.29 × 71.70
  4. Step 4: Simplify right side
    77.10x = 7,620.99
  5. Step 5: Solve for x
    x = 7,620.99/77.10
  6. Step 6: Final answer
    x = 98.85

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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.