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Finding the Fourth Proportional to 120.80, 180.33 and 103.79

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Solution

The fourth proportional to 120.80, 180.33 and 103.79 is: 154.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.80 : 180.33 = 103.79 : x
  2. Step 2: Convert to fraction form
    120.80/180.33 = 103.79/x
  3. Step 3: Cross multiply
    120.80x = 180.33 × 103.79
  4. Step 4: Simplify right side
    120.80x = 18,716.51
  5. Step 5: Solve for x
    x = 18,716.51/120.80
  6. Step 6: Final answer
    x = 154.93

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.