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Finding the Fourth Proportional to 120.55, 166.29 and 76.21

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Solution

The fourth proportional to 120.55, 166.29 and 76.21 is: 105.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.55 : 166.29 = 76.21 : x
  2. Step 2: Convert to fraction form
    120.55/166.29 = 76.21/x
  3. Step 3: Cross multiply
    120.55x = 166.29 × 76.21
  4. Step 4: Simplify right side
    120.55x = 12,672.55
  5. Step 5: Solve for x
    x = 12,672.55/120.55
  6. Step 6: Final answer
    x = 105.12

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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.