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Finding the Fourth Proportional to 128.88, 192.36 and 120.24

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Solution

The fourth proportional to 128.88, 192.36 and 120.24 is: 179.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.88 : 192.36 = 120.24 : x
  2. Step 2: Convert to fraction form
    128.88/192.36 = 120.24/x
  3. Step 3: Cross multiply
    128.88x = 192.36 × 120.24
  4. Step 4: Simplify right side
    128.88x = 23,129.37
  5. Step 5: Solve for x
    x = 23,129.37/128.88
  6. Step 6: Final answer
    x = 179.46

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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.