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Finding the Fourth Proportional to 77.60, 106.66 and 72.56

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Solution

The fourth proportional to 77.60, 106.66 and 72.56 is: 99.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.60 : 106.66 = 72.56 : x
  2. Step 2: Convert to fraction form
    77.60/106.66 = 72.56/x
  3. Step 3: Cross multiply
    77.60x = 106.66 × 72.56
  4. Step 4: Simplify right side
    77.60x = 7,739.25
  5. Step 5: Solve for x
    x = 7,739.25/77.60
  6. Step 6: Final answer
    x = 99.73

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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.