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Finding the Fourth Proportional to 216.28, 298.34 and 128.89

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Solution

The fourth proportional to 216.28, 298.34 and 128.89 is: 177.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.28 : 298.34 = 128.89 : x
  2. Step 2: Convert to fraction form
    216.28/298.34 = 128.89/x
  3. Step 3: Cross multiply
    216.28x = 298.34 × 128.89
  4. Step 4: Simplify right side
    216.28x = 38,451.55
  5. Step 5: Solve for x
    x = 38,451.55/216.28
  6. Step 6: Final answer
    x = 177.79

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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.