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Finding the Fourth Proportional to 77.79, 106.70 and 76.47

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Solution

The fourth proportional to 77.79, 106.70 and 76.47 is: 104.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.79 : 106.70 = 76.47 : x
  2. Step 2: Convert to fraction form
    77.79/106.70 = 76.47/x
  3. Step 3: Cross multiply
    77.79x = 106.70 × 76.47
  4. Step 4: Simplify right side
    77.79x = 8,158.97
  5. Step 5: Solve for x
    x = 8,158.97/77.79
  6. Step 6: Final answer
    x = 104.88

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.