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Finding the Fourth Proportional to 236.92, 355.20 and 128.80

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Solution

The fourth proportional to 236.92, 355.20 and 128.80 is: 193.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    236.92 : 355.20 = 128.80 : x
  2. Step 2: Convert to fraction form
    236.92/355.20 = 128.80/x
  3. Step 3: Cross multiply
    236.92x = 355.20 × 128.80
  4. Step 4: Simplify right side
    236.92x = 45,749.76
  5. Step 5: Solve for x
    x = 45,749.76/236.92
  6. Step 6: Final answer
    x = 193.10

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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.