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Finding the Fourth Proportional to 125.25, 187.65 and 81.86

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Solution

The fourth proportional to 125.25, 187.65 and 81.86 is: 122.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    125.25 : 187.65 = 81.86 : x
  2. Step 2: Convert to fraction form
    125.25/187.65 = 81.86/x
  3. Step 3: Cross multiply
    125.25x = 187.65 × 81.86
  4. Step 4: Simplify right side
    125.25x = 15,360.09
  5. Step 5: Solve for x
    x = 15,360.09/125.25
  6. Step 6: Final answer
    x = 122.64

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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.