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Finding the Fourth Proportional to 217.31, 300.21 and 142.80

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Solution

The fourth proportional to 217.31, 300.21 and 142.80 is: 197.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.31 : 300.21 = 142.80 : x
  2. Step 2: Convert to fraction form
    217.31/300.21 = 142.80/x
  3. Step 3: Cross multiply
    217.31x = 300.21 × 142.80
  4. Step 4: Simplify right side
    217.31x = 42,868.13
  5. Step 5: Solve for x
    x = 42,868.13/217.31
  6. Step 6: Final answer
    x = 197.27

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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.