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Finding the Fourth Proportional to 137.22, 205.50 and 85.86

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Solution

The fourth proportional to 137.22, 205.50 and 85.86 is: 128.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.22 : 205.50 = 85.86 : x
  2. Step 2: Convert to fraction form
    137.22/205.50 = 85.86/x
  3. Step 3: Cross multiply
    137.22x = 205.50 × 85.86
  4. Step 4: Simplify right side
    137.22x = 17,644.23
  5. Step 5: Solve for x
    x = 17,644.23/137.22
  6. Step 6: Final answer
    x = 128.58

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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.