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Finding the Fourth Proportional to 75.20, 103.76 and 66.56

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Solution

The fourth proportional to 75.20, 103.76 and 66.56 is: 91.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.20 : 103.76 = 66.56 : x
  2. Step 2: Convert to fraction form
    75.20/103.76 = 66.56/x
  3. Step 3: Cross multiply
    75.20x = 103.76 × 66.56
  4. Step 4: Simplify right side
    75.20x = 6,906.27
  5. Step 5: Solve for x
    x = 6,906.27/75.20
  6. Step 6: Final answer
    x = 91.84

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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.