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Finding the Fourth Proportional to 66.20, 91.34 and 38.55

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Solution

The fourth proportional to 66.20, 91.34 and 38.55 is: 53.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.20 : 91.34 = 38.55 : x
  2. Step 2: Convert to fraction form
    66.20/91.34 = 38.55/x
  3. Step 3: Cross multiply
    66.20x = 91.34 × 38.55
  4. Step 4: Simplify right side
    66.20x = 3,520.96
  5. Step 5: Solve for x
    x = 3,520.96/66.20
  6. Step 6: Final answer
    x = 53.19

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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.