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Finding the Fourth Proportional to 120.32, 180.48 and 91.79

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Solution

The fourth proportional to 120.32, 180.48 and 91.79 is: 137.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.32 : 180.48 = 91.79 : x
  2. Step 2: Convert to fraction form
    120.32/180.48 = 91.79/x
  3. Step 3: Cross multiply
    120.32x = 180.48 × 91.79
  4. Step 4: Simplify right side
    120.32x = 16,565.86
  5. Step 5: Solve for x
    x = 16,565.86/120.32
  6. Step 6: Final answer
    x = 137.68

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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.