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Finding the Fourth Proportional to 128.90, 194.12 and 108.02

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Solution

The fourth proportional to 128.90, 194.12 and 108.02 is: 162.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.90 : 194.12 = 108.02 : x
  2. Step 2: Convert to fraction form
    128.90/194.12 = 108.02/x
  3. Step 3: Cross multiply
    128.90x = 194.12 × 108.02
  4. Step 4: Simplify right side
    128.90x = 20,968.84
  5. Step 5: Solve for x
    x = 20,968.84/128.90
  6. Step 6: Final answer
    x = 162.68

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.