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Finding the Fourth Proportional to 128.34, 192.15 and 109.08

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Solution

The fourth proportional to 128.34, 192.15 and 109.08 is: 163.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.34 : 192.15 = 109.08 : x
  2. Step 2: Convert to fraction form
    128.34/192.15 = 109.08/x
  3. Step 3: Cross multiply
    128.34x = 192.15 × 109.08
  4. Step 4: Simplify right side
    128.34x = 20,959.72
  5. Step 5: Solve for x
    x = 20,959.72/128.34
  6. Step 6: Final answer
    x = 163.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.