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Finding the Fourth Proportional to 128.39, 176.72 and 119.12

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Solution

The fourth proportional to 128.39, 176.72 and 119.12 is: 163.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.39 : 176.72 = 119.12 : x
  2. Step 2: Convert to fraction form
    128.39/176.72 = 119.12/x
  3. Step 3: Cross multiply
    128.39x = 176.72 × 119.12
  4. Step 4: Simplify right side
    128.39x = 21,049.41
  5. Step 5: Solve for x
    x = 21,049.41/128.39
  6. Step 6: Final answer
    x = 163.96

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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.