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Finding the Fourth Proportional to 217.38, 299.59 and 155.21

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Solution

The fourth proportional to 217.38, 299.59 and 155.21 is: 213.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.38 : 299.59 = 155.21 : x
  2. Step 2: Convert to fraction form
    217.38/299.59 = 155.21/x
  3. Step 3: Cross multiply
    217.38x = 299.59 × 155.21
  4. Step 4: Simplify right side
    217.38x = 46,499.36
  5. Step 5: Solve for x
    x = 46,499.36/217.38
  6. Step 6: Final answer
    x = 213.91

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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.