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Finding the Fourth Proportional to 216.28, 298.57 and 138.70

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Solution

The fourth proportional to 216.28, 298.57 and 138.70 is: 191.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    216.28 : 298.57 = 138.70 : x
  2. Step 2: Convert to fraction form
    216.28/298.57 = 138.70/x
  3. Step 3: Cross multiply
    216.28x = 298.57 × 138.70
  4. Step 4: Simplify right side
    216.28x = 41,411.66
  5. Step 5: Solve for x
    x = 41,411.66/216.28
  6. Step 6: Final answer
    x = 191.47

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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.