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Finding the Fourth Proportional to 217.40, 300 and 138.74

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Solution

The fourth proportional to 217.40, 300 and 138.74 is: 191.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.40 : 300 = 138.74 : x
  2. Step 2: Convert to fraction form
    217.40/300 = 138.74/x
  3. Step 3: Cross multiply
    217.40x = 300 × 138.74
  4. Step 4: Simplify right side
    217.40x = 41,622
  5. Step 5: Solve for x
    x = 41,622/217.40
  6. Step 6: Final answer
    x = 191.45

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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.