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Finding the Fourth Proportional to 75.75, 104.31 and 66.57

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Solution

The fourth proportional to 75.75, 104.31 and 66.57 is: 91.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.75 : 104.31 = 66.57 : x
  2. Step 2: Convert to fraction form
    75.75/104.31 = 66.57/x
  3. Step 3: Cross multiply
    75.75x = 104.31 × 66.57
  4. Step 4: Simplify right side
    75.75x = 6,943.92
  5. Step 5: Solve for x
    x = 6,943.92/75.75
  6. Step 6: Final answer
    x = 91.67

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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.