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Finding the Fourth Proportional to 142.91, 214.31 and 85.25

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Solution

The fourth proportional to 142.91, 214.31 and 85.25 is: 127.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.91 : 214.31 = 85.25 : x
  2. Step 2: Convert to fraction form
    142.91/214.31 = 85.25/x
  3. Step 3: Cross multiply
    142.91x = 214.31 × 85.25
  4. Step 4: Simplify right side
    142.91x = 18,269.93
  5. Step 5: Solve for x
    x = 18,269.93/142.91
  6. Step 6: Final answer
    x = 127.84

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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.