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Finding the Fourth Proportional to 120.79, 166.68 and 77.18

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Solution

The fourth proportional to 120.79, 166.68 and 77.18 is: 106.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.79 : 166.68 = 77.18 : x
  2. Step 2: Convert to fraction form
    120.79/166.68 = 77.18/x
  3. Step 3: Cross multiply
    120.79x = 166.68 × 77.18
  4. Step 4: Simplify right side
    120.79x = 12,864.78
  5. Step 5: Solve for x
    x = 12,864.78/120.79
  6. Step 6: Final answer
    x = 106.51

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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.