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Finding the Fourth Proportional to 128.26, 191.30 and 120.16

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Solution

The fourth proportional to 128.26, 191.30 and 120.16 is: 179.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.26 : 191.30 = 120.16 : x
  2. Step 2: Convert to fraction form
    128.26/191.30 = 120.16/x
  3. Step 3: Cross multiply
    128.26x = 191.30 × 120.16
  4. Step 4: Simplify right side
    128.26x = 22,986.61
  5. Step 5: Solve for x
    x = 22,986.61/128.26
  6. Step 6: Final answer
    x = 179.22

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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.