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Finding the Fourth Proportional to 217.40, 326.10 and 121.40

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Solution

The fourth proportional to 217.40, 326.10 and 121.40 is: 182.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.40 : 326.10 = 121.40 : x
  2. Step 2: Convert to fraction form
    217.40/326.10 = 121.40/x
  3. Step 3: Cross multiply
    217.40x = 326.10 × 121.40
  4. Step 4: Simplify right side
    217.40x = 39,588.54
  5. Step 5: Solve for x
    x = 39,588.54/217.40
  6. Step 6: Final answer
    x = 182.10

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.