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Finding the Fourth Proportional to 217.05, 299.50 and 123.80

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Solution

The fourth proportional to 217.05, 299.50 and 123.80 is: 170.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.05 : 299.50 = 123.80 : x
  2. Step 2: Convert to fraction form
    217.05/299.50 = 123.80/x
  3. Step 3: Cross multiply
    217.05x = 299.50 × 123.80
  4. Step 4: Simplify right side
    217.05x = 37,078.10
  5. Step 5: Solve for x
    x = 37,078.10/217.05
  6. Step 6: Final answer
    x = 170.83

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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.