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Finding the Fourth Proportional to 216.08, 298.14 and 128.78

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Solution

The fourth proportional to 216.08, 298.14 and 128.78 is: 177.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.08 : 298.14 = 128.78 : x
  2. Step 2: Convert to fraction form
    216.08/298.14 = 128.78/x
  3. Step 3: Cross multiply
    216.08x = 298.14 × 128.78
  4. Step 4: Simplify right side
    216.08x = 38,394.47
  5. Step 5: Solve for x
    x = 38,394.47/216.08
  6. Step 6: Final answer
    x = 177.69

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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.