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Finding the Fourth Proportional to 236.80, 355.38 and 128.68

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Solution

The fourth proportional to 236.80, 355.38 and 128.68 is: 193.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    236.80 : 355.38 = 128.68 : x
  2. Step 2: Convert to fraction form
    236.80/355.38 = 128.68/x
  3. Step 3: Cross multiply
    236.80x = 355.38 × 128.68
  4. Step 4: Simplify right side
    236.80x = 45,730.30
  5. Step 5: Solve for x
    x = 45,730.30/236.80
  6. Step 6: Final answer
    x = 193.12

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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.