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Finding the Fourth Proportional to 228.43, 315.20 and 128.84

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Solution

The fourth proportional to 228.43, 315.20 and 128.84 is: 177.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    228.43 : 315.20 = 128.84 : x
  2. Step 2: Convert to fraction form
    228.43/315.20 = 128.84/x
  3. Step 3: Cross multiply
    228.43x = 315.20 × 128.84
  4. Step 4: Simplify right side
    228.43x = 40,610.37
  5. Step 5: Solve for x
    x = 40,610.37/228.43
  6. Step 6: Final answer
    x = 177.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.