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Finding the Fourth Proportional to 216.45, 298.67 and 138.78

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Solution

The fourth proportional to 216.45, 298.67 and 138.78 is: 191.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.45 : 298.67 = 138.78 : x
  2. Step 2: Convert to fraction form
    216.45/298.67 = 138.78/x
  3. Step 3: Cross multiply
    216.45x = 298.67 × 138.78
  4. Step 4: Simplify right side
    216.45x = 41,448.73
  5. Step 5: Solve for x
    x = 41,448.73/216.45
  6. Step 6: Final answer
    x = 191.49

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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.