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Finding the Fourth Proportional to 236.78, 355.20 and 212.78

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Solution

The fourth proportional to 236.78, 355.20 and 212.78 is: 319.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    236.78 : 355.20 = 212.78 : x
  2. Step 2: Convert to fraction form
    236.78/355.20 = 212.78/x
  3. Step 3: Cross multiply
    236.78x = 355.20 × 212.78
  4. Step 4: Simplify right side
    236.78x = 75,579.46
  5. Step 5: Solve for x
    x = 75,579.46/236.78
  6. Step 6: Final answer
    x = 319.20

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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.